Atomic bombings of Hiroshima and Nagasaki

Atomic bombings of Hiroshima and Nagasaki

The atomic bombings of Hiroshima and Nagasaki, the last American strategic bombing of Japan, took place on August 6 and August 9, 1945, on the cities of Hiroshima (340,000 inhabitants) and Nagasaki (195,000 inhabitants). Hiroshima was the headquarters of the 5th division of the Second General Army and the command center of General Shunroku Hata, and Nagasaki was chosen as the target rather than the historic city of Kyoto.

General information
Date August 6 and August 9, 1945
Location Hiroshima and Nagasaki, Empire of Japan
Issue Surrender of Japan
USA Empire of Japan
Opposing forces
United States Air Force
Hiroshima 68,000 to 140,000 dead
Nagasaki 35,000 to 80,000 dead
Total 103,000 to 220,000 dead
Second World War Pacific War Key Data
Coordinates 34° 23′ 41″ N, 132° 27′ 17″ E

Using the pretext of the Japanese leadership’s rejection of the terms of the ultimatum of the Potsdam Conference, the United States wished to impose on Japan its unconditional surrender, the ouster of Emperor Hirohito and the adoption of a democratic political regime. The US government also wishes, since the A-bomb is now operational (Little Boy uranium, Fat Man plutonium), to test it in real life and show other countries, especially the USSR, the decisive fire superiority it gives to America, which makes these bombings a harbinger of the Cold War. These bombings, which some consider one of the main war crimes of the Allies, remain the only use of nuclear weapons during a conflict.

It is finally on August 14, following these bombings, but also the Soviet invasion of Manchuria started on August 8 and the surrender of the Japanese Kwantung Army on August 10, Let the Japanese government give in and accept its surrender. Less than a month later, the signing of the Acts of Surrender of Japan on September 2, 1945, in Tokyo Bay marked the end of World War II.

The number of people killed by the explosion, heat and subsequent firestorm is difficult to determine and only estimates are available, ranging from 103,000 to 220,000 deaths, not counting subsequent cases of cancer (several hundred) or other side effects. The survivors of the explosions, the hibakusha, have become the symbol of a struggle against war and atomic weapons throughout the world.

The impact of these bombings raised fears later of the use of atomic weapons in a nuclear war, an effect at the basis of nuclear deterrence that weighed heavily in the strategic choices of the Cold War.

Preparatives of the bombings

On the right, Robert Oppenheimer, the father of the bomb, with Leslie Groves, general in charge of the Manhattan Project
On the right, Robert Oppenheimer, the “father” of the bomb, with Leslie Groves, general in charge of the Manhattan Project

A long-term project

Codenamed the Manhattan Project, the secret program to research and build a nuclear weapon was launched in 1942, less than seven months after the United States entered the war. with the assistance of the United Kingdom and Canada under the Quebec Agreement signed in 1943, and the participation of many European scientists.

The two bombs used against Japan (Little Boy uranium and Fat Man plutonium) are respectively the second and third to have been built and remain the only ones deployed since that date in a theatre of operations. They were preceded by the first experimental bomb code-named Trinity in New Mexico in July 1945.

In December 1944, the 509e USAAF Bomber Squadron was formed under the command of Colonel Paul Tibbets to drop these bombs once they were built; it was deployed to Tinian in May and June 1945.

This squadron is equipped with B29 bombers from a special series, manufactured for the atomic bombings, called “Silverplate”, named after the USAAF participation program in the Manhattan Project. He trains using conventional bombs, but built to the size of atomic bombs, the “pumpkin bombs”.

The two bombers that will drop their bombs on Hiroshima and Nagasaki, Enola Gay and Bockscar, belong to this special series.


Trinity is the name of the very first test of a plutonium atomic bomb, nicknamed “Gadget” in part because it is not an operational weapon. It takes place in the New Mexico desert, on July 16, 1945, at Alamogordo Air Force Base and demonstrates the effectiveness of a nuclear weapon.

Four days later, the modified B-29s of the 509e bombing squadron began conducting training raids against Japanese cities with conventional bombs of the shape and weight of atomic bombs; other missions took place on the 24th, July 26 and 29. Japanese fighters did not attempt to intercept aircraft that their bombing altitude of 9,100 m protected against DCA.

Choice of targets

Participants (Manhattan Project Deputy Director Thomas Farrell, Captain William Sterling Parsons, mathematicians and physicists John von Neumann and William Penney) at the ” Objectives Committee Target Committee) at Los Alamos on 10 and May 11, 1945, select targets on Japanese territory in the following order:

  • Kyoto (city of the ancestors of the Tennō dynasty and former capital of Japan, the psychological impact was considered particularly interesting);
  • Hiroshima (the city of the ancestors of Chōshū Domain, it was one of the country’s main military bases during the Sino-Japanese War (1894-1895) and the terrain configuration lent itself to an attack by air detonation);
  • Yokohama (which finally suffered a conventional bombing raid on May 29, 1945);
  • the Kokura arsenal (already hit during the bombing of Yahata in June 1944);
  • Niigata;

Of these targets, the first two are classified “AA”, the next two “A”, the fifth “B”. The possibility of targeting the imperial palace in Tokyo had been discussed, but this option was not recommended since Tokyo had already been heavily bombed elsewhere.

According to Robert Jungk, in his book Brighter than a Thousand Suns:

“On the short list of targets for the atomic bomb, in addition to Hiroshima, Kokura and Niigata, there was also the city of temples, Kyoto. When the expert on Japan, Professor Edwin O. Reischauer, heard this terrible news, he hurriedly went to the office of his chief, Major Alfred MacCormack, in a department of Army Intelligence. The shock made him burst into tears. MacCormack, a cultured lawyer who respected human life, persuaded Secretary of War Henry L. Stimson to grant Kyoto a reprieve and remove the city from the list. »

Reischauer refutes this version in his book My Life Between Japan And America, 1986, p.101:

“I probably would have done that if I had the chance, but this story doesn’t contain an ounce of truth. As has already been amply proven by my friend Otis Cary of Doshisha in Kyoto, the only person who deserves honors for saving Kyoto from destruction is Henry L. Stimson, the Secretary of War at the time, who had known and admired Kyoto on his honeymoon more than three decades earlier. »

This claim is partially confirmed by Richard Rhodes, who describes Stimson’s refusal to bomb Kyoto, going against the wishes of General Leslie Groves.

Kyoto, which had been put at the top of the list in an earlier version of the list because it was the former imperial capital, was replaced by another city, at the request of Secretary of War Henry Lewis Stimson, because of its cultural value; It had also been spared the incendiary bombing for the same reasons. Nagasaki is therefore retained in its place.

On May 31, 1945, Henry L. Stimson convened the interim committee. Participants discussed whether to send the Japanese a warning before the attack. They feared that the Japanese would move prisoners of war to the areas intended for bombing or that the bombers would be shot down. It may also be that the bomb is a fiasco with an incomplete explosion. Edward Teller proposes to detonate the night bomb, without warning, over Tokyo Bay to avoid loss of life and shock the public. This idea is rejected: the Japanese had already proven their unlimited fighting spirit with suicide bombers and it is not certain that an action without mass destruction is enough to destabilize them.

Oppenheimer suggests attacking with several bombs on the same day to stop the war once and for all. General Groves opposes this because the targets have already been the subject of conventional bombing and the effects of the bombs will not be significant enough on these already devastated terrains. Moreover, the estimates of the power of a nuclear explosion then available correspond at best to only half, at worst to one-tenth of the effective power. As no trials have been conducted, the effects are not yet known. Only after the Trinity trial can the nature of the mission be decided.

Operations trigger

For several months, the Japanese government had instructed the USSR, the only country that had not declared war on Japan, to make unofficial offers of armistices to the United States.

On July 26, the United States, the United Kingdom and China transmitted the Potsdam Declaration calling for Japan’s unconditional surrender, the removal of the emperor, and warning that the country would be devastated if the war continued. The Japanese government rejected the Allied requests on July 28 (mokusatsu).

Japan’s Reaction to the Potsdam Ultimatum

The exchanges between Hirohito, the cabinet, and the general staff show that the Empire of Japan was not about to surrender unconditionally. Japanese records and the diary of the Keeper of the Seals Kōichi Kido indicate that the emperor and cabinet insisted on conditional surrender, while the government was conducting parallel negotiations with the Soviet Union.

Among these conditions were the disarmament of troops by the Japanese authorities, the trial of criminals by the Japanese authorities, the absence of occupying forces on Japanese soil, and the preservation of the imperial regime and the Emperor. For many historians, including Jacques Pauwels, the clause of the impeachment of the Emperor was introduced only to make the ultimatum of Potsdam unacceptable while Japan bloodied and whose civilian population had been martyred by the incendiary bombs (especially those dropped on Tokyo in March 1945) was ready to surrender. The real goal was to allow the Americans to use atomic weapons to show their power against the Soviets.

In response to the Potsdam Declaration of 26 July, the Japanese government held a press conference on 28 July, at which Prime Minister Kantarō Suzuki announced Japan’s intention to “ignore” (mokusatsu) the ultimatum. An ambiguity remains, however, as to Suzuki’s attitude: in favor of capitulation, he had to deal with the warmongering faction of the army, and perhaps wished, by this expression, to express a simple refusal to address the issue in public, or to mean that the ultimatum brought nothing new. However, the term is understood by the United States as a categorical refusal of any surrender.

Between July 27 and August 6, while Hirohito was under intense pressure from his brothers and his uncles who asked him to abdicate in favor of his son, the government took refuge in silence. Pending a conclusion to the negotiations with the Soviets, the emperor ordered the Keeper of the Seals Kôichi Kido on 31 July to take measures to defend “at all costs” the imperial insignia

On August 2, Shigenori Tōgō, the Minister of Foreign Affairs, transmitted a message to the Japanese ambassador in Moscow, Naotake Satō, telling him that the Emperor, the Prime Minister and the Imperial General Headquarters “pinned all their hopes” in the Soviet Union’s acceptance of a peace mission led by Prince Fumimaro Konoe. The ambassador responded by recommending that the government accept the terms of the Potsdam.

Pressed by the emperor, eager to protect his prerogatives, Tōgō refused any direct negotiations with the other allies even when Kaina, the president of the spy bureau told him on August 4: “It is not enough to negotiate only with the Soviet Union. There is no hope if we continue like this. Somehow, behind the scenes, we have to negotiate with the United States, Britain and China”.

The order to attack

General Spaatz, head of the U.S. Air Force Combat Command
General Spaatz, head of the U.S. Air Force Combat Command

On July 21, 1945, President Harry S. Truman approves dropping bombs on Japan. On July 24, the order was relayed by Secretary of War Henry Lewis Stimson, and the next day, General Thomas Handy sent a secret order to General Spaatz, authorizing the dropping of the bomb after August 3, “as soon as time permits”, on Hiroshima, Kokura, Niigata or Nagasaki. This will be the only written order regarding the use of the atomic bomb. Spaatz is responsible for informing Mac Arthur and Nimitz. The order does not mention the nature of the explosive, merely mentioning a special bomb. This order was given even before the Potsdam ultimatum was published.

Only a few people were aware of President Truman.


This city was, after Kyoto, Japan’s main city of art and history, with a civilian population of about 250,000.

Hiroshima during World War II

Capital of the Chūgoku region on the delta of the Ota-gawa River, the city is established on seven islands.

Military camps were set up in the vicinity. Among the most important were those of the 5e division and the command center of General Shunroku Hata. He managed the entire defense of the southern part of the archipelago. The headquarters of the Second General Army (第2総軍 (日本軍), Dai-ni Sōgun) established on April 8, 1945, from the dissolution of the General Defense Command (防衛総司令部, Bōei Soshireibu) was located in a mountainous sector of the city 10 km from the center, in Hiroshima Castle.

Hiroshima was an important supply center and logistics base for the armed forces. There was a communications center, equipment and troop depots. The population of Hiroshima was mobilized, as in other Japanese cities, against the American invader: women and children learned to fight with sticks and to endure the war effort whether in offices or factories.

At about 50 km from the city, on the island of Ōkunoshima, was established a toxic gas manufacturing plant affiliated with the Shiro Ishii Research Unit Network. With the expansion of the Empire, during the Showa era, different types of chemical weapons were produced there such as mustard gas, mustard gas, yperite, lewisite and cyanide. These products were used against Chinese soldiers and civilians as well as in experiments conducted on human guinea pigs by Shiro Ishii’s units. However, this installation was not targeted by bombing, since it was too far from Hiroshima.

The city was chosen as a target, as it had not yet suffered any air raid. According to the Hiroshima National City Museum, the city was deliberately spared by the Americans during conventional bombing to avoid any prior damage, in order to better assess the effects of the bomb.

The city was made of houses almost all built of light wood frame and paper. The center of the city had several public buildings made of reinforced concrete. On the outskirts, wooden dwellings rubbed shoulders with small shops, forming a dense collection of light structures. A few factories were located away in the suburbs. The risk of fire was high in Hiroshima: the concentration of buildings and materials used were conducive to maximum destruction because of the thermal effects of the atomic bomb.

Information about the number of people present in the city during the bombing varies widely, ranging from 255,000 to 348,000 inhabitants. The estimates given by troops and workers are probably imprecise. The American report showing 255,000 inhabitants was based on rice rationing statistics for June 1945.


The atomic bomb Little Boy before its installation in the cargo bay of the B-29
The atomic bomb Little Boy before its installation in the cargo bay of the B-29

Two hours after the successful Trinity test on July 16, 1945, bombs Fat Man and Little Boy were sent from San Francisco to Tinian aboard the cruiser Indianapolis. On July 26, 1945, they arrived on the American base. On 28 July and the following day, four planes of the “Green Hornet line” flew from Australia to bring the last components needed for the bombs: the plutonium core for Fat Man and the uranium cylinders for Little Boy.

U.S. Navy Captain William Parsons was responsible for maintaining and organizing the assembly of the bombs on site. He set up the various workshops necessary for this operation, as it was not yet known how many bombs would be used to bend Japan. The Americans had planned two more attacks if the first did not prove sufficient. The bomb for a second attack was thus already ready, and meanwhile, in the United States, the production of fissile material continued for the manufacture of a third bomb.

The only possible delivery vehicle for the bomb was the Boeing B-29 Superfortress, the only heavy bomber capable of reaching Japan at the time. About twenty examples were modified by combining the two bomb bays into one, to house the new weapon, during the summer of 1945 at the Glenn L. Martin factory in Omaha. A unit specially created for the nuclear bombing was formed, the 509th Composite Group.

Little Boy was installed in a B-29, but was not armed. There were fears that the plane would crash and the bomb would accidentally go off, immediately pulverizing much of the island. Accidents with these bombers were common and the military did not want to take risks. It was decided that armament, one of the most delicate phases of the mission, would be done after takeoff. The team trained tirelessly to refine the mission and especially Parsons who was responsible for arming the bomb in flight with all the responsibilities that entailed.

Captain Paul Tibbets then decided to name the B-29 after his mother, Enola Gay, to place the aircraft and its crew “under a lucky star” as he will say it in an interview. Shortly before takeoff, journalists gathered around the bomber to capture the event.

The bombing

Hiroshima was the priority target for the bombing. On August 6, 1945, the weather was clear over the city. Several B-29s (including Jabbit III for Kokura and Full House for Nagasaki) had been sent to the other targets to assess the weather situation, in case conditions were unfavorable over Hiroshima, but the other cities were all covered by clouds. Piloted by Paul Tibbets, Enola Gay had started at 2 h 45 on Tinian Island, with Little Boy on board. It was armed during the flight by Captain William Parsons.

The crew of Enola Gay with Paul Tibbets in the center
The crew of Enola Gay with Paul Tibbets in the center

About an hour before the bombing, the Japanese had detected the approach of an American plane on the south of the archipelago. The alert was triggered with announcements to the population and the interruption of radio programs in several cities. The plane flew over Hiroshima and disappeared. This aircraft was actually the B-29 reconnaissance, Straight Flush, which reported good visibility conditions for the bombing. Japanese radars then detected a new group of aircraft at high altitude, but their small number, only three, caused the alert to be lifted after about ten minutes. The recommendations for the population were to reach the shelters if a B-29 was visible, but no raid was expected except reconnaissance.

These were actually the three B-29s of the Hiroshima raid that were flying at more than 9,500 meters above sea level:

  • Enola Gay (bombing);
  • The Great Artiste (measurements and data collection);
  • Necessary Evil (photographs, films).

Second Lieutenant Morris R. Jeppson was the last to touch the bomb when he placed the armament fuses. Shortly before 8h15, Enola Gay arrived over the city. The order to bomb was given by Tibbets and Major Thomas Ferebee executed it by aiming at the Aioi Bridge, recognizable by its “T” shape, which was an ideal landmark in the center of the city. Shortly after 8h15, the bomb “Little Boy” came out of the cargo bay at an altitude of 9,450 m (31,000 feet).

On August 6, 1945, at 8h16 min 2 s, after about 43 seconds of free fall, activated by altitude sensors and radars, it exploded at 580 meters vertical of Shima Hospital, in the heart of the city, at about 300 m southeast of the originally targeted bridge, releasing energy equivalent to about 15,000 tons of TNT. The explosion instantly killed tens of thousands of people and destroyed everything on about 12 km2.

A huge bubble of glowing gas more than 400 meters in diameter formed in fractions of a second, emitting powerful thermal radiation. Below, near the hypocenter, the temperature of the surfaces exposed to this radiation rose for a brief moment, very superficially, to perhaps 4,000 °C. Fires broke out, even several kilometers away. People exposed to this flash were burned. Those protected inside or by the shadows of the buildings were buried or injured by the projection of debris when a few seconds later the shock wave arrived on them. Winds of 300 to 800 km/h devastated streets and homes. The long ordeal of the survivors was just beginning as the mushroom cloud, sucking in dust and debris, began its mile-long ascent and began spitting out its contaminated dust.

A huge widespread outbreak quickly triggered with temperature peaks in some places. While some areas were spared during the explosion, they later had to face a deluge of fire caused by the intense movements of the air masses. This “firestorm” was similar to those caused by the firestorming of German cities.

Enola Gay had meanwhile made a sharp 155° turn to the northwest and was turning back. The crew members, protected by glasses, were able to witness the explosion. Bob Lewis, the co-pilot of Enola Gay, exclaims, “My God, what have we done?”.

The six American aircraft involved in the attack returned undamaged to the Marianas at Tinian where Major General Carl Spaatz, head of the 8e Air Force, decorated Tibbets with the Distinguished Service Cross and the rest of the crew of the Distinguished Flying Cross. A quick debriefing was conducted by the intelligence officer and the crew was invited for drinks at the officers’ club. The other two B-29s tasked with collecting data and shots stayed long enough around the blast site to photograph the mushroom cloud and damage, film the surroundings, and gather information about the mission.

Tokyo authorities discovered the destruction

The operator in charge of radio links in Tokyo, an employee of the Nippon Hōsō Kyōkai, noticed that the Hiroshima station was no longer responding. He tried to re-establish communication via another telephone line, but it was also silent. About twenty minutes later, the railway center that managed the telegraphs in Tokyo realized that the main line had stopped working to the north of Hiroshima. All of these issues were reported to the Japanese command post.

The main command repeatedly tried to call the army command center in Hiroshima. The ensuing silence left Tokyo officials dubious. They knew that no enemy raids with large numbers of aircraft had taken place, radars had reported only a few scattered aircraft. Moreover, there were no large stockpiles of explosives in Hiroshima at the time. A young officer from Japanese headquarters was then rushed to Hiroshima by plane to survey the damage and return to Tokyo with information of potential destruction. It was thought to be just a few lines cut by an isolated bombardment.

The officer went to the airport and his plane headed southwest. After three hours of flight, he and his pilot saw a huge cloud of smoke over Hiroshima. However, the aircraft was still at 160 km. Once there, the two men kept circling the devastated city, unable to believe what they saw: fires for miles around and a thick cloud dominating the city transformed into a field of ruins. The plane landed south of the city and the officer took action informing Tokyo.

The capital would not be informed of the exact cause of the disaster until sixteen hours later, when the White House publicly announced the bombing in Washington.

Meanwhile, in Hiroshima, help was slow to come and many perished in the first hours. An intense thirst won the inhabitants, the victims were desperately looking for water, but the soldiers had been ordered not to give drink to the burn victims.

Japanese government reaction

The atomic bombing came at a time in the war when the United States was ” carrying out one of the most intense campaigns to destroy urban centers in world history. 68 Japanese cities were bombed, and all were partially or completely destroyed”. The American air offensive will cause a total of more than a million deaths and wounded, mostly by these conventional means. The August 13, General Anami Korechika, Minister of War, declares that the atomic bombs are no “worse” than the napalm incendiary bombs that have ravaged the country for weeks.

The bombing of Hiroshima did not change the attitude of Hirohito and the government, which took no action to initiate the surrender process, still hoping for a favorable outcome to the negotiations with the Soviet Union. On August 7, Shigenori Tōgō again inquired with Ambassador Satō about the intentions of the Soviet government.

USSR Reaction

Taking advantage of the bombing of Hiroshima, Stalin put an end to negotiations with Japan and launched, on August 9, ten minutes after midnight, the Manchurian offensive, i.e. three months after the German capitulation, as agreed at the Yalta.

Second ultimatum

After the attack, a speech by President Truman announced that the United States had used an atomic bomb against Hiroshima and that further air attacks would be carried out against Japanese industries and transportation networks. The declaration also threatened Japan with a “deluge of ruins from the air like never before seen on this Earth” if it did not accept an unconditional surrender:

“The force from which the sun draws its power has been unleashed against those who started the war in Asia. (…) It was to spare the Japanese people from total destruction that the ultimatum of July 26 was formulated at the Potsdam Conference. Its leaders immediately rejected this ultimatum. If they do not accept our terms now, they must expect a deluge of destruction like never before seen on this Earth. After this air attack will follow marine and land forces in numbers and power such as they have never seen before and with the combat skills of which they are already well aware.”

This time, the Japanese government made no official response, focusing on a way to obtain assurances from the Soviet Union that the Kokutai and the emperor’s prerogatives would be protected.

Two days later, night incendiary bombardments were conducted by the US Air Force against the towns of Yawata and Fukuyama; these attacks destroyed 21% of the Yawata urban area and more than 73% of the Fukuyama. The Japanese aircraft intercepted the formation sent against Yawata and shot down one B-29 and five P-47s while losing about 12 fighters.

American Messages to the Japanese People

In parallel with exchanges between governments, on August 8, 1945, messages printed on small sheets of paper were dropped on Japan:


America asks that you immediately pay attention to what you are going to read on this sheet.

We are in possession of the most destructive explosive ever devised by man. Only one of our atomic bombs, which we have recently developed, is equivalent to the explosive power that 2,000 B-29s can carry on a single mission. This awful statement should make you think, and we can solemnly assure you that it is terribly accurate.

We have just started using this weapon against your homeland. If you have any doubt, investigate and ask what happened in Hiroshima when only one of our bombs fell on the city.

Before using this bomb to destroy all the military resources that allow this useless war to continue, we ask you to petition the Emperor to end the conflict. Our President has set out the thirteen conditions for an honourable surrender. We urge you to accept these conditions and begin the process of building a new, better and peaceful Japan.

You should make decisions now to stop the military resistance. Otherwise, we will have to resolve to use this bomb and all our other superior weapons to quickly and forcefully cease this war.”


Nagasaki during World War II

The city of Nagasaki was one of the largest ports in southern Japan and was a mainstay of the Japanese military-industrial complex. Various industries were located there: military equipment and munitions factories, shipyards, aircraft factories, etc.

Japan’s extensive war effort required modern means that contrasted with the rest of Nagasaki: the residences were traditional, with wooden structures. The walls were made of wood with sometimes plaster and the roofs were covered with tiles. Smaller factories and commercial buildings were also constructed of wood. The structures could not withstand strong explosions.

Nagasaki expanded for several years without really following a specific plan. The houses were placed near the factories in the valley and the density of buildings was high. Before the atomic attack, Nagasaki had never been subjected to large-scale bombing. On the 1st August 1945, some high-powered bombs were dropped on the city. Some of these bombs hit the port and shipbuilding in the southwestern part of the city. Other bombs targeted Mitsubishi factories and three out of six bombs hit the Nagasaki hospital. Despite limited damage, the impact on the population was significant: some of the children were evacuated to rural areas, along with other people.

The bombing

The mushroom cloud on Nagasaki rose to an altitude of 18 km
The mushroom cloud on Nagasaki rose to an altitude of 18 km

The second atomic bombing took place on August 9, 1945. Departing from Tinian, the B-29 bomber Bockscar was originally scheduled to drop the “Fat Man” bomb on the city of Kokura but its pilot, Charles Sweeney, decided to return to the secondary target of Nagasaki because of cloud cover over the city. Two more B-29s took off soon after: The Great Artiste piloted by Frederick Bock and Big Stink flown by Lieutenant Colonel Hopkins.

After ten minutes of flight, Commander Ashworth activated the bomb by loading the fuses and ordered not to descend below 1,500 meters to avoid accidental detonation. The three planes were scheduled to rendezvous over Yaku-shima Island, but Bockscar only encountered The Great Artist. For more than 40 minutes, the two bombers circled the island to wait for it. Meanwhile, weather information from reconnaissance planes arrived: clouds partially covered Nagasaki and Kokura, but bombing was normally possible.

The other plane did not appear, so the two B-29s headed for Kokura. Arriving above the city around 10h20, the crew of Bockscar faced a new problem: 70% cloud cover prevented bombing. After three overflights of Kokura, the two planes headed for Nagasaki, the second target, to visually bomb the city’s main factories. The tens of minutes spent waiting for The Big Stink allowed Kokura to avoid bombing following a sudden deterioration in weather conditions, and sealed Nagasaki’s fate.

Bockscar however had to face a new unforeseen event with the impossibility of having reserve fuel.

At 7h50, an air alert was given in Nagasaki but was quickly lifted around 8h30. When the planes appeared over the city around 10h56, the Japanese thought they were reconnaissance planes, then common, and no alarm was given.

Minutes before the bomb exploded, The Great Artiste dropped scientific instruments attached to three parachutes. Messages to Japanese professor Ryōkichi Sagane, a nuclear physicist who had worked with three of the members of the Manhattan Project, accompanied the parachuted equipment. The messages asked him to warn the Japanese public of the dangers of the atomic bomb, but they were not found until the end of the war.

At 11h2, a breakthrough in the clouds over Nagasaki allowed the Bockscar bomber, Captain Kermit Beahan, to target the planned area, a valley with industries. Fat Man was then dropped and exploded at 469 meters above sea level. The explosion took place between the two potential targets: the Mitsubishi Steel and Armaments Plant to the north and the Mitsubishi-Urakami Torpedo Plant to the south.

The bomb was dropped at 10h58 local time and the explosion with a power of 20 kilotons destroyed 3.8 km2 of buildings in Urakami district.

Three shockwaves reached both planes. The Great Artiste continued its scientific mission around Nagasaki while Bockscar headed south. The return to Tinian was impossible due to a lack of reserve fuel, so Bockscar might have to land at sea. Sweeney decided to land in Okinawa, then under American occupation. It was almost while hovering that the bomber arrived on the runway, an engine had already stopped in flight. About twenty minutes later, The Great Artist landed accompanied by The Big Stink who had headed solo to Nagasaki to take pictures.

The three aircraft refueled and returned to Tinian, arriving undamaged on 9 August at 23h30.

The Soviet invasion of Manchuria also began on August 9 and the Red Army advanced rapidly.

On the same day, the B-29s dropped three million leaflets on Japanese cities warning that atomic bombs would be used to destroy all of the country’s military assets unless the emperor ended the war.

This bombing had no bearing on the Japanese surrender decision.

The Third Atomic Bomb

A third atomic bomb was to be assembled at the end of August, eight more bombs were to be available in November and General George Marshall, the Chief of Staff of the U.S. Army requested that they be placed in reserve to target tactical targets in support of the invasion of Japan.

Human and material consequences of the two nuclear explosions


The U.S. Department of Energy (DOE) puts the figure at 70,000 for Hiroshima and 40,000 for Nagasaki. For its part, the Hiroshima Peace Memorial Museum puts the figure at 140,000 dead, in the city of Hiroshima alone. According to historian Howard Zinn, the number of victims reached 250,000. To these are added the deaths caused later by various types of cancer (334 cancers and 231 leukemias in the population monitored, less than 2,000 in total according to an American source) and pathologies.

Hiroshima victims

The number of victims will probably never be known because the circumstances (partly evacuated city, presence of refugees from other cities, destruction of civil status archives, simultaneous disappearance of all members of the same family, mass cremations) make any exact accounting impossible, especially of the deaths that occurred in the first hours:

  • according to a 1946 estimate, the population at the time of the attack was 245,000, 70,000 to 80,000 of them were killed and as many wounded;
  • according to a 1956 estimate, out of a population of 256,300 people, 68,000 were killed and 76,000 wounded;
  • according to another more recent one, out of a population of 310,000 people, 90,000 to 140,000 of them were killed;
  • according to the mayor of Hiroshima during a speech in 2005, the total death toll would be 237,062, but this number remains hypothetical.

According to a sampling study conducted in November 1945 by Tokyo Imperial University School of Medicine, 73.5% of the victims died either in the bombing or on the same day. 11.3% of victims died before the end of the first week, and 3.4% in the second week; Overall, nearly nine-tenths of the victims (88.3%) died in this first two-week period. The remainder died mostly (9.9% of victims) after three to eight weeks, and a few (1.4% of victims) after three to four months.

According to the same study, but on a different sample, 26.2% of victims died on the first day of unknown causes, 45.5% died of “mechanical” causes following the blast of the explosion and fires (crushing, trauma, burns); 16.3% burns due to the “thermal flash” of the nuclear explosion; and 12.0% of radiation outcomes. If we consider that unknown causes are essentially “mechanical” causes, this category is responsible for more than 70% of deaths.

Nagasaki victims

Famous photo of Sumiteru Taniguchi after the Nagasaki explosio
A famous photo of Sumiteru Taniguchi after the Nagasaki explosion

As in Hiroshima, the number of victims in Nagasaki has been the subject of several estimates. According to the same sources:

  • according to the 1946 estimate: 35,000 people were killed and slightly more injured;
  • according to that of 1956: out of a population of 173,800, 38,000 were killed and 21,000 wounded;
  • from the most recent: out of a population of 250,000, 60,000 to 80,000 of them were killed.

There are some peculiarities in Nagasaki compared to Hiroshima:

  • the weapon used being more powerful (a power equivalent to about 20,000 tons of TNT) the damage near the hypocenter seems to have been greater ;
  • thanks to the hills, the destruction was less extensive because the relief protected some neighborhoods;
  • the habitat being more diffuse, the violence of the fires was more limited, they took two hours to take important proportions, with a duration of a few hours and there was no generalized conflagration ;
  • the weapon being of a different model (plutonium bomb instead of a uranium bomb) the distribution of radiation γ and neutrons was different, which seems to have changed the frequency of the types of leukemias observed.

Thermal radiation and fire injuries

These types of injuries, found in 65% of injured survivors in Hiroshima and Nagasaki, were responsible for perhaps 50% of the deaths, caused by several mechanisms:

  • burns of the skin discovered by the thermal radiation emitted for a fraction of a second at the time of the explosion. The slightest opaque obstacle may have provided some protection: the wearing of clothing, especially light, the shade of buildings, the foliage of trees… This is perhaps the most characteristic injury of a nuclear explosion;
    • first degree burns (erythema suggestive of sunburn) were observed more than 4 km (occasionally 5 km) of the hypocenter,
    • third-degree burns (fatal if extensive) on bare skin up to 1.5 km (occasionally 2.5 km),
    • people near the hypocenter whose body parts were exposed to lightning were instantly charred to the hypodermis. They agonized from a few minutes to a few hours.

It is estimated that thermal radiation was the direct cause of about 20-30% of deaths in Hiroshima and Nagasaki:

    • burns by flames: Many fires broke out in the city after the explosion: in twenty minutes, the fires gathered in a single generalized hearth, causing the appearance of a column of hot air and strong winds. This firestorm lasted 16 hours and devastated 11 km2, which left little chance for the victims, often already injured, who were trapped there. Unlike conventional incendiary bombing, the Hiroshima attack severely limited the population’s ability to flee by destroying a large area. It was only when all the fuel was exhausted that the fire stopped. The number of deaths related to the fires is undoubtedly very high but impossible to estimate, because many bodies were destroyed by the flames.

A side effect, but just as deadly, was the appearance of a large amount of carbon monoxide. This gas caused asphyxiation in the middle of the fire and there were certainly few survivors. However, no testimony confirms the assertion of a massive release of CO;

  • finally, those who, further away, had their eyes pointed at the fireball had their retinas burned or damaged, which caused blindness. While they could be reversible, this sudden inability to move prevented large numbers of people from finding shelter and escaping death as the fires developed.


Le Monde diplomatique of August 2005 publishes some extracts from a text by the American journalist John Hersey published on 31 August 1946 in the New Yorker. Hersey was one of the first to visit the site, and he describes the phenomenon of Hiroshima shadows: “The first Japanese scientists who arrived a few weeks after the explosion noted that the flash of the bomb had discolored the concrete. In some places, the bomb had left marks corresponding to the shadows of the objects that its lightning had illuminated. For example, experts had found a permanent shadow cast on the roof of the Chamber of Commerce building by the tower of the same building. Human silhouettes were also found on walls, such as photo negatives.

This phenomenon is due to changes in the chemical composition of the materials exposed and “burned” by the intense radiation of the nuclear fireball, radiation that could be intercepted by various obstacles. This is similar to what happens when you project color on a hand on a sheet of paper (the stencil technique). The heat (several thousand degrees Celsius) released by the bomb ” was absorbed by the bodies, so that the ground under these bodies received less heat and was protected by them”.

Shock wave and blast injuries

These types of injuries were found in 70% of injured survivors in Hiroshima and Nagasaki, but they were rarely serious. The most likely hypothesis is that immobilized the seriously injured were condemned when the fires developed in the rubble.

  • barotrauma (direct effect): internal damage by rupture of the eardrums, sinuses, lungs or digestive tract due to the sudden change in pressure at the passage of the wave. Such lesions have been poorly observed (lesions of the eardrums, the most fragile organ, have been found in less than 10% of survivors close to the hypocenter);
  • indirect effect, and probably much more deadly:
    • the passage of the shock wave caused the collapse of the buildings (up to 2 km in the case of wooden dwellings). It is estimated that a large number of victims died buried under the rubble, especially as fires developed rapidly,
    • broken, wood, glass and other building materials turned into deadly projectiles. Injured people had lacerations up to 2 km of the hypocentre,
    • blast abruptly moved the victims and injured them by falling or crushing.


There are several causes of irradiation:

  • the main cause was instantaneous irradiation at the time of the explosion (external irradiation by neutrons and γ rays emitted by the nuclear reactions in the bomb). It represented a lethal dose for 50% of people exposed outdoors (4 Gy) at just over a 1 km distance from the hypocentre. The buildings, especially the concrete ones, provided some protection
  • much less important (because the bomb exploded far from the ground) is the irradiation by the induced radioactivity: at the time of the explosion, the bombardment by neutrons made the materials near the hypocenter radioactive by the formation of radionuclides. This radioactivity decreased rapidly and remained confined to an area where thermal radiation had normally already killed almost everything. It is estimated that on the first day, at most, a cumulative dose of 0.6 Gy. From the second to the fifth day, it was less than 0.1 Gy. In a few days it became insignificant;
  • even less important, the irradiation following radioactive fallout: that is to say, irradiation by radionuclides produced during the explosion and falling from the atomic cloud in the form of dust or black rain. In Hiroshima, the explosion having been aerial, there was relatively little fallout because the cloud rose rapidly to a very high altitude where the radionuclides dispersed (maximum total cumulative ground dose of 0.4 Gy).

Signs of radiation were found in 30% of injured survivors in Hiroshima and Nagasaki, possibly responsible for 5-15% of the deaths, often by acute radiation syndrome. The exact number of deaths related to acute radiation syndrome is difficult to determine because most of these victims also had extensive thermal burns, quickly fatal with general symptomatology quite similar. No effect of radiation was demonstrated beyond 2.4 km of the hypocenter:

  • the main manifestation was therefore acute radiation syndrome: from a few days to a few weeks after the attack, the irradiated victims presented a phase of prodromes with asthenia, headache, nausea and vomiting. After a latency phase of a few days to a few weeks during which the state of health of the victims seemed to improve, worsening occurred with asthenia, headache, nausea, vomiting, diarrhea, immunosuppression, hair loss, hemorrhages and possibly death. After 4 months and in the absence of deaths, the evolution was oriented towards recovery;
  • exposure in utero of fetuses, as a result of irradiation of pregnant women. Deaths in utero (abortion), growth retardation, mental retardation or malformations (non-hereditary) have been observed.

Long-term health effects of irradiation

  • Leukemias: From 1947, an increase in the incidence of leukemia was observed among irradiated survivors. A peak was reached in 1951, then this incidence declined to disappear in 1985. Out of 49,204 irradiated survivors followed from 1950 to 2000, there were 94 cases of fatal radiation leukemia;
  • cancerous tumors: Follow-up of irradiated survivors has shown, from the late 1950s, a gradual increase in the incidence of cancers, particularly those of the lung, digestive tract and breast. Out of 44,635 irradiated survivors followed between 1958 and 1998, there were 848 cases of fatal cancers attributable to radiation;
  • medical effects other than cancer in irradiated survivors: occurrence of cataracts, sterility (often reversible in humans), an increase in the frequency of (non-cancerous) pulmonary, cardiac or digestive diseases with a possible decrease in lifespan. The number of these deaths seems to be equal to the number or half the number of those due to cancer and leukemia (about 0.5% to 1%).

The number of deaths due to the long-term effects of nuclear bombing is, according to these figures, paltry compared to the number of victims in the first months. In March 2007 in Japan, nearly 252,000 people still alive were considered “hibakusha” (survivors of the bomb). But of these, less than 1% (2,242 to be exact) are recognized as suffering from a disease caused by radiation.

Effects on irradiated progeny

The results of the follow-up of the descendants of the victims of Hiroshima and Nagasaki (30,000 children of irradiated parents, which represents a statistically significant population) did not allow to observe an increase in malformations or genetic disorders.

Radioactive fallout

A few hours after the explosion, the atomic cloud had reached a significant vertical development and caused rainfall. It contained radioactive dust and ash that gave it a hue close to black, and was therefore referred to as “black rain” in Anglo-Saxon literature. The raindrops were as big as marbles.

The fallout of fission products from the rain was relatively limited compared to that from a ground explosion (see Castle Bravo). They covered an area of 30 × 15 km northwest of the point of explosion; and they are estimated to have resulted in a cumulative external exposure of 1.8 to 44 rad, i.e. 18 to 440 mGy (at most of the order of 0.5 Sievert). These figures correspond to a cumulative exposure, i.e. to reach such an exposure, it would have been necessary to park at the hour following the explosion and for six weeks in a row at the most radioactive point detected.

These exposure levels are insufficient to cause the deterministic effects of acute radiation syndrome, but for the most highly exposed people (more than 0.1 Sv), they can lead to low long-term stochastic effects (e.g. 0.5 Sv (maximum) could theoretically correspond to a cancer risk of 2.5%).

The majority of radiation casualties were caused by direct exposure to radiation at the time of the explosion (see below).

Of the survivors, 171,000 became homeless.

Construction strength

The reinforced concrete buildings in central Hiroshima were designed according to anti-seismic standards. Their structure generally withstood the stresses caused by the explosion. The bomb having exploded at altitude, admittedly low, and not on the ground, the blast had a direction more or less perpendicular to the ground, which may have limited the damage. The strength and protection offered by these structures are evidenced by the following figures: the chances of still being alive twenty days later were 50% for people who were at the time of the explosion at:

  • 200 m of the hypocenter in a concrete building (but chance of final survival: 12%);
  • 675 m in a building (not specified) ;
  • 2 km outside a building.

The “dome”, Hiroshima’s industrial promotion center designed by Czech architect Jan Letzel, was very close to the hypocenter. This building resisted the blast and was renamed Hiroshima Peace Memorial. It has been part of the UNESCO monuments since 1996 despite the protests of the United States and China.

As a rule, traditional wooden constructions were completely destroyed by blast up to a distance of 2 km from the hypocenter. Beyond and up to 3 km the damage was significant but repairable, provided they survived the fires that followed.

After the bombings

Media coverage of bombings

The nuclear bombing of Hiroshima was announced by the White House on August 6, sixteen hours after the explosion, in a long statement from President Truman. The statement gives few details about the explosion: it evokes the extraordinary power of the new weapon but only announces that “Hiroshima is no longer useful to the enemy”.

It contains an allusion to the race to the bomb by indicating that fortunately, the Germans who had developed the V1 and V2 missiles, did not also have nuclear weapons. But above all, the text insists on the collaboration between the British and the Americans, and on the need they were faced with to carry out the program on American soil, and not in the United Kingdom, which is too exposed. And finally, the president seeks to reassure public opinion: he announces the benefits of the atom that will constitute a new source of energy alongside coal, oil and water, but the public must understand that secrecy – and new research – are still necessary; nevertheless, democratic control is announced, through a commission that the United States Congress will be responsible for establishing.

The American press makes its headlines and its first articles of these few information.

The New York Times devoted a long article to the event on its next day August 7, which makes extensive mention of the presidential communiqué, and the subsequent press conference of the Secretary of State for War, which states that one “still does not know what happened in Hiroshima. The War Department indicated that a precise report was not yet available because the target was hidden from reconnaissance aircraft by an impenetrable cloud of dust and smoke.

In the absence of other evidence, the newspaper mentions the information given by the War Department on the New Mexico test: a huge metal tower was vaporized, a cloud formed up to 40,000 feet (12,000 meters), and two observers located 10,000 yards away (about 9 km) were thrown to the ground. It also repeats passages from Truman’s communiqué on the conditions for the development of the weapon, and emphasizes the tone of solemnity and seriousness with which the officials spoke.

The newspaper also reported Churchill’s reaction:

“By the grace of God, we defeated the Nazis in the race for the Bomb!”

It also quotes information given by the United Press agency: according to the British minister in charge of aircraft production, the bomb weighs 400 pounds (less than 200 kg) and is capable of razing a city.

As for the usefulness of the media coverage of the bombing, the New York Times summarizes the two antagonistic positions as follows: reveal it, or keep it secret.

“It is certain that the authorities at the highest level took the important decision to reveal the existence of the atomic weapon because of the psychological effect it could have on the Japanese decision to surrender. However, some officials allow themselves to say privately that it would have been better to keep it secret. Their opinion can be summed up in this comment from a spokesman: why bother with psychological warfare against an enemy already defeated and who does not have enough common sense to lay down his arms and avoid total destruction?

Hiroshima made headlines in the American press: the San Francisco Chronicle headline, for example: Japan hit by an atomic bomb, the most powerful weapon in history! The article presents Hiroshima as a military base, which the bomb completely destroyed. The Washington Post writes:

“Even if we deplore this necessity (to attack with the atomic bomb), a fight to the death forces all combatants to inflict maximum damage on the enemy and this in the shortest period of time. (…) We express our unreserved gratitude to science for giving us this new weapon before the end of the war.

The international press mainly repeats information disseminated by Western news agencies (Reuters, United).

In France, the newspaper Le Monde headlined in its August 8 edition: A scientific revolution, the Americans drop their first atomic bomb on Japan. The article repeats the main elements of the presidential communiqué, and the public intervention of Secretary of War Stimson, which Truman had announced. Le Monde mentions that Stimson predicts that Japan will be unable to respond to nuclear weapons, and that it will be a valuable help in shortening the war.

The Argentine daily Critica of 8 August explains that “all human, animal and plant life disappeared in Hiroshima, the government has ordered the evacuation of major cities” and quotes a Reuters news agency that there have been more than 100,000 dead, burned alive or killed by heat and pressure. The newspaper also quotes a Japanese action broadcast on Radio Tokyo, picked up in Argentina:

“The use of the atomic bomb against Hiroshima is yet another example of the evil nature of the enemy, who has no qualms about slaughtering civilians.”

Radio-Tokyo is also quoted to evoke the effects of the bomb:

“… The dead and wounded are burned beyond recognition. The authorities are unable to find solutions for civilian victims.

The newspaper also quotes a report by the United agency that Tokyo is appealing to international law, the Japanese believing that the United States has violated Article 22 of the Hague Convention. The Japanese broadcast in French a program to Europe to explain that Hiroshima could not be a military objective, and use the French expression “demilitarized city”. United does not fail to point out that Japan has not ratified the Hague Convention, and that it makes no mention of its own bombing of Manila and Chinese cities. United finally indicated that the American government intended to proceed with the invasion of the Japanese archipelago, but that the course of this operation would depend on the effect of the bomb on the combativeness of the Japanese.

The danger of radiation is not mentioned by the press: acute radiation syndrome was unknown to medicine at the beginning of August 1945 and therefore to the authorities and the military. It was the Japanese doctors who discovered it a few weeks later.

In the editorial of Combat of 8 August 1945, Albert Camus presents his analysis of the situation:

“… Thanks to the tremendous concert that radio, newspapers and news agencies have just unleashed about the atomic bomb […] we are told […] in the midst of a host of enthusiastic comments that any medium-sized city can be totally leveled by a bomb the size of a football. American, English, and French newspapers spread elegant essays on the future, the past, the inventors, the cost, the peaceful vocation and the warlike effects, the political consequences and even the independent character of the atomic bomb. We will summarize ourselves in one sentence: mechanical civilization has just reached its last degree of savagery.

On August 7, according to the USAF and General Spaatz, reconnaissance planes were able to take photographs: 4.1 square miles of urban area were destroyed, 60% of the city was destroyed. The New York Times recalls that the pre-war population was 348,000 and indicates that General Spaatz explained that the area mentioned was completely destroyed as well as five large industrial facilities, and that there is damage beyond the zone of total destruction. He states that the flash of the explosion was seen by another B29 170 miles from the target.

On August 7 and 8, 1945, no newspaper was published in Hiroshima. Thirty-five years later, on August 6, 1980, a special edition “Hiroshima Tokuho” (the ghost diary) reported the facts as if the explosion had just occurred and its three reporters accompanied by a cameraman were advancing in the direction of the hypocenter.

The bombing of Nagasaki was in turn announced in the international press, with another event occurring almost at the same time: the declaration of war by the Soviets, who immediately invaded Manchuria.

The New York Times of August 9, 1945 states that “the second use of this new and terrifying secret weapon that wiped out more than 60 percent of the city of Hiroshima and, according to Japan Radio, killed virtually its entire population, took place around noon today.” The newspaper also quotes a Radio Tokyo program, which vigorously protests the bombing: “How will U.S. military officials escape their degradation, Not only in the eyes of other nations, but also in the eyes of the American people? What do the justice-loving American people think of their leaders who commit a crime against man and against God?

The Third Bomb

The third bomb would have been of the Fat Man type (model Mark MK III)
The third bomb would have been of the “Fat Man” type (model Mark MK III)
Schema of Fat Man
Schema of Fat Man

After the bombing of Nagasaki and the Soviet Union’s entry into the war against Japan on August 9, negotiations became active. The end of the war seemed near, but the United States was preparing to launch a third bomb in case the first two missions were not enough. Captain William Parsons was not allowed to leave the island of Tinian until the surrender. It was to ensure the supply and assembly of additional bombs if Japan persisted in the conflict. The U.S. military wanted the Japanese to believe that they had an unlimited number of nuclear weapons. The theories about the third bomb are multiple but the testimonies overlap on one point: an additional bomb could not be ready for a few weeks.

It is also believed that the military had a great deal of leeway on Truman’s part. Stanley Goldberg points out that it was probably General Groves who had the final say on the bombing of Nagasaki. Groves had to demonstrate the importance of this bombshell to explain the huge investment made for the Manhattan Project.

In General Spaatz’s archives, it is mentioned that the USAAF wanted to drop the third bomb on Tokyo if the Japanese did not surrender their arms quickly enough. In response to this request, it was stated that the decision had already been made and that the target would be Sapporo on the island of Hokkaido.

Major Charles Sweeney, Bockscar pilot, took part in the last raid against Japan on August 14, 1945. The most important B-29s (Enola Gay and Bockscar) remained in Tinian, as did The Great Artist which contained all the equipment needed to analyze another atomic explosion. Two B-29s flew to the United States to load equipment and components for the assembly of an additional bomb.

Richard Frank claims that General Marshall and General Groves had delayed the transport of the third bomb and that it could not be available until August 21, 1945. According to Chuck Hansen, the United States had two Fat Man bombs at the end of 1945, but the exact date of their assembly is unknown. In any case, the subcontractors had received orders during the summer of 1945 for a large quantity of components, which were canceled after the Japanese surrender.

As for scientists at Los Alamos National Laboratory, several testimonies agree that a plutonium core was being manufactured and delivered. Oppenheimer himself ordered, without an explicit order from Truman, not to charge the radioactive material that was to take the road to San Francisco. This piece of plutonium was likely to arrive in Tinian around August 20.

Surrender of Japan

GI's based in Paris learning of Japan's surrender (August 1945)
GI’s based in Paris learning of Japan’s surrender (August 1945)
Imperial Conference on August 14 at which Emperor Shōwa
Imperial Conference on August 14 at which Emperor Shōwa (left) informed members of the Supreme Council of his intention to announce the surrender of the Empire of Japan on the grounds that the Potsdam ultimatum and the U.S. Secretary of State’s response offered sufficient guarantees for the preservation of the throne and imperial rule

The Soviet invasion of Manchukuo precipitated Hirohito’s decision. On August 9, he asked his Keeper of the Seals Kōichi Kido to organize an imperial conference to “control the situation” because “the Soviet Union has declared war and launched hostilities against us”. During this conference held on the night of the 9th to the 10th, the Emperor announced his decision to surrender to the ultimatum of the allies and requested the preparation of an imperial declaration on the condition that this declaration “does not prejudice His Majesty’s prerogatives as Sovereign”.

On the 12th, Hirohito officially informed the imperial family of his decision. Prince Yasuhiko Asaka, one of the Emperor’s uncles, then asked him: “Will the war continue if the imperial institution and national policy (kokutai) cannot be preserved?” To which Hirohito replied laconically: “Of course”.

On the 14th, while an attempted mutiny by a small group of soldiers opposed to surrender was put down, Hirohito approved the imperial declaration, and the next day his disc-recorded address to the Japanese people was broadcast on radio. The atomic bomb is clearly mentioned: “the enemy has implemented a new bomb of extreme cruelty, whose destructive capacity is incalculable and decimates many innocent lives. If We continued to fight, it would lead not only to the collapse and annihilation of the Japanese nation, but also to the complete extinction of human civilization. The Soviet Union’s entry into the war is not mentioned.

On the 17th, he issued an “edict to soldiers and sailors” ordering them to lay down their arms and linking his decision to surrender to the Soviet invasion of Manchukuo, ignoring the atomic bombings.

The arrival of the Americans

On August 28, 1945, the Americans landed on the archipelago under the command of General George Marshall. Groups of experts were sent to Hiroshima and Nagasaki. They must report on the situation both at the human and military level with the destruction of buildings. The Japanese are surprised by the elegance of these officers who begin to interview hundreds of people. These testimonies will make it possible to better estimate the effects of bombs on the population.

The special envoys are all stunned by the extent of the damage. On September 5, journalist Wilfred Burchett published an account in the Daily Express:

“In Hiroshima, thirty days after the first atomic bomb that destroyed the city and shook the world, people who were not hit during the cataclysm, are still dying mysteriously, horribly, from an unknown evil for which I have no other name than that of atomic plague.

Dr. Katsube, whom he interviewed, described to him the cutaneous and hematopoietic forms of acute radiation syndrome, of which he discovered and observed the first known manifestations:

“They lost their appetite, their hair fell out, bluish spots appeared on their bodies, and they began to bleed, from their noses, mouths and eyes. The symptoms were generalized weakness and severe vitamin deficiency. We gave them vitamin injections, but the flesh was necrotic around the hole made by the needle of the syringe. And in any case, the patient dies. We know that something has destroyed their white blood cells, and there is nothing we can do.

As soon as it surrendered, Japan was under American tutelage. The country will suffer a similar fate to Germany with the arrest of the main dignitaries. Like the Nuremberg Tribunal, the Tokyo Tribunal convicted the accused for their war crimes, including Hideki Tōjō, who was hanged on December 22, 1948. Emperor Hirohito was not threatened and remained on the throne until his death in 1989.

The Civil Censorship Detachment (CCD) set up in Japan by the US occupation forces had about 6,000 employees in 1946. They are responsible for listening to communications and limiting the power of the press. Journalists are not allowed to investigate the atomic bombs and the effects seen in the two destroyed cities.

On 3 November 1946, the new constitution, modeled on the wishes of the Allied forces, was adopted and definitively validated on 7 May 1947. The United States occupied Japan until April 1952. Some islands were not returned to Japan until the 1970s.

Comparative analysis of American bombing

Groups of U.S. military experts, sent to Japan immediately after the atomic explosion to analyze the damage, estimated that the bomb on Hiroshima was equivalent to an air raid by 220 B-29s carrying 1,200 tons of incendiary bombs, 400 tons of high-yield bombs and 500 tons of cluster bombs.

For comparison, the bombing of Dresden, one of the largest bombings of World War II that lasted 3 days, required 580 bombers (B-17 and Avro Lancaster). A total of 1,554 tons of conventional bombs and 164 tons of incendiary bombs destroyed the city. The number of deaths varies according to the sources, ranging from 25,000 and 135,000 dead.

Hamburg suffered a similar fate during Operation Gomorrah, but over a period of about 10 days with 2,714 aircraft and 8,650 tons of conventional bombs that killed 40,000 people. Historians estimate that the total number of Germans killed in bombing during World War II is between 305,000 (US Strategic Bombing Report in 1945) and 600,000.

Censorship and publication of images

In September 1945, the Nippon Eigasha company sent crews of cameramen to film in Nagasaki and Hiroshima. But on October 24, 1945, an American military policeman forbade a Japanese cameraman to continue filming in Nagasaki. Nippon Eigasha’s films were then confiscated by the Americans and classified as a defense secret.

In addition, rushes constituting a total of 27 km of film were filmed at that time by the teams of Lieutenant Daniel A. McGovern for the U.S. Strategic Bombing Survey, a US military organization responsible for evaluating strategic bombing. Gradually demanded by the Japanese government, made public and saved from oblivion, the first black and white archive films were not shown to both Japanese and American audiences until the late 1960s or early 1970s. It was not until the 1980s for the first color films. The documentary Original Child Bomb by Carey Schonegevel published in 2004 still revealed unpublished images. Moreover, according to Jean-Marie Bouissou, director of the Asia program at Sciences Po Paris, photos of the victims of the two bombings could still be classified as secret by the Japanese and American governments.

Debate on the decision to proceed with the bombings

Controversies over the aims of these bombings

The decision to drop the bombs on Japan was made by President Truman for several reasons that historians have tried to analyze, Weigh or discard:

  • satisfy public opinion by avenging soldiers killed on the Pacific front;
  • reduce the duration of the war and avoid a landing on the archipelago, which American strategists believed would have an extremely high human cost;
  • make a show of force towards the rest of the world and in particular towards the Soviet Union;
  • contribute to strategically counter the Soviet Union by taking position on all the Japanese islands, in order to avoid a partition as in Germany, and to create thanks to occupied Japan an American beachhead on the west coast of the Pacific, to limit Soviet ambitions;
  • test in real scale a deterrent strike force;
  • justify a program whose cost was exorbitant.

Whether or not the atomic bombings were necessary is still a controversial issue. Indeed, according to the terms of Article 6b of the Statute of the International Military Tribunal, adopted by the Allies themselves in the London Agreements of 8 August 1945, the day after the Hiroshima explosion and the day before the Nagasaki explosion, these bombings constitute war crimes of the Allies, as pointed out, among others, by the philosopher Hannah Arendt and the prosecutor at the Nuremberg trials, Telford Taylor.

The Case for Bombing

Despite a discreet diplomatic channel that began with the Japanese civil authorities in January 1945 (after the invasion of Luzon to the Philippines), supporters of the bombing pointed to the intransigence of the Japanese military, which refused to negotiate. While some members of the civilian government made efforts toward peace, they did not have the power to secure a ceasefire, let alone surrender. As monarchy, the “Land of the Rising Sun” could only begin the path of peace with the support of the Japanese cabinet. But it was dominated by members of the imperial army and navy, who did not want to give in under any circumstances. A split then appeared between the army and the civilian power.

The will of resistance of the Japanese

Battle of Okinawa: Flamethrower cleansing of a Japanese shelter by an American soldier
Battle of Okinawa: “Flamethrower cleansing” of a Japanese shelter by an American soldier

Historian Victor Davis Hanson highlights the growing resistance of the Japanese, a determination that appears futile after the fact since the conflict was doomed to an inevitable outcome according to him. The Battle of Okinawa showed the ability of the Japanese to fight at any cost, with Japanese soldiers even going so far as to commit suicide rather than surrender, thus applying the traditional codes of “the way of the warrior” (Bushido). Bruno Birolli also points out that at the beginning of August 1945, the Japanese resistance remained fierce: the American army, despite an armada superior to that implemented during the Normandy landings, struggled to take Okinawa Island. It was inconceivable for the authorities that foreigners would set foot on the sacred soil of Japan.

More than 110,000 Japanese and 12,520 Americans were killed in the bloodiest clash of the Pacific War. The “Marines” used flamethrowers and grenades to eliminate the last pockets of resistance. The last Japanese forces, the kamikazes, swept through the American and Allied ships, causing heavy casualties. This battle (April to the end of June 1945) ended only two months before the surrender of Japan.

Major General Masakazu Amanu, chief of the operations section at Army Headquarters, was confident in his defensive structures, which he had meticulously prepared from the beginning of 1944. According to him, the Allies could not invade the islands of the archipelago. With the determination of its army, Japan was convinced to win.

Nor did the Japanese fear the Soviets; When they declared war on Japan on August 8, 1945, and launched Operation August Storm, invading northern China and Korea, the Imperial Army ordered its last forces in Manchuria to hold out and fight to the death.

After the destruction of Hiroshima, the civilian power tried to convince the military that surrendering on the terms of the Potsdam Conference was the only solution. After the annihilation of Nagasaki, Emperor Hirohito had to intervene himself to unblock the political situation in the country. The two cities became a shock argument against the continuation of the conflict. Kōichi Kido, one of the emperor’s close advisors, stated “We, the supporters of peace, were aided by the atomic bomb in our quest to stop the war”. Hisatsune Sakomizu, the chief cabinet secretary in 1945, described the bombing as “a golden opportunity from the sky that allows Japan to cease the war.

Several historians agree that the civilian opposition put forward arguments that were sufficient to convince the military of the futility of continuing the war: neither the boundless courage of the soldiers nor the determination in combat could help Japan against total destruction by atomic weapons.

The human cost of a prolongation of hostilities

On August 15, 1945, Japan surrendered
On August 15, 1945, Japan surrendered. On September 2 aboard the Missouri in Tokyo Bay, General Yoshijiro Umezu signed the surrender to General Douglas MacArthur

Proponents of nuclear bombing argued that waiting for Japan to surrender was not an option without consequences.

Philippine judge Delfin Jaranilla, a member of the Tokyo tribunal charged with trying some of the Shōwa regime’s war criminals, wrote in obiter dictum in his judgment:

“If a means is justified by an end, the use of the atomic bomb was justified because it brought Japan to its knees and brought about the end of this horrible war. If the war had lasted longer, without the use of the atomic bomb, how many thousands and thousands of defenseless men, women and children would have suffered and died…?

The continued bombing of Japanese cities

Several times a week waves of B-29s loaded with incendiary devices attacked large and medium-sized settlements of the archipelago. The extent of the damage was largely comparable in order of magnitude to nuclear attacks. While these raids were less lethal at the time, their long-term effects were also terrible, depriving hundreds of thousands of people of shelter, clothing and resources, which in these times of famine could mean death.

Destroyed urban areas (excluding nuclear bombing) (in km2) from June to August 1945
1-7 June 8-14 June 15-21 June 22-30 June 1-7 July 8-14 July 15-21 July 22-31 July August 1-7 8-14 August
25.2 0 37.2 10.2 31.3 20.93 18.4 20.5 27.45 5.1

The Hiroshima attack destroyed 12 km2, while the Nagasaki attack destroyed 6 km2.

The Blockade of Japan

By the summer of 1945, the blockade of Japan was almost complete. U.S. submarines and aircraft had control of coastal waters. Supplemented by large-scale mining (Operation Starvation), imports and transport of goods between the different islands of the archipelago came to an almost complete halt. The disorganization of the country’s economy was to become complete with the attack by aviation on domestic lines of communication (railways…), ending up isolating the cities from each other.

If this operation made it possible to reduce Japanese industrial production to nothing, its human consequences were not zero. Since Japan was a food importer, the average per capita ration had fallen from 2,000 calories before the war to 1900 in 1944, before dropping to 1,650 in the summer of 1945. This situation of malnutrition would undoubtedly have worsened with the prolongation of hostilities. Starvation and disease would then have been responsible for an even heavier toll than that of atomic bombs.

The Invasion of Japan

The Americans planned from the end of 1945 a land invasion of Japan, Operation Downfall. Its duration and human cost depended heavily on the resistance of the imperial army and the Japanese population to the invader. It was to be divided into two parts:

  • operation Olympic: the invasion of Kyūshū in November 1945 by 767,000 Allied soldiers, five times more than for the Normandy landings, led by 156,000 men
  • if Operation Olympic had been insufficient to achieve surrender, Operation Coronet on Honshū and Tokyo in March 1946 with twice as many men as Olympic, involving a massive redeployment of US combat troops from Europe.

American losses

On June 18, 1945, in a meeting with President Truman, General Marshall estimated that the losses (killed, wounded, missing) of the first 30 days of the invasion of Kyūshū could amount to 31,000. But Admiral Leahy pointed out that they could also be proportional to those of the Battle of Okinawa, making the toll much more expensive. Indeed, in Okinawa, 180,000 Americans faced 120,000 Japanese for three months: American losses amounted to 48,000 (almost a third of the force engaged). With Operation Olympic, 767,000 U.S. troops would have faced perhaps 600,000 Japanese troops.

And the operation Coronet would have been even more deadly: 1.4 million Americans would have faced from 2 to 3 million of Japanese until perhaps the end of 1946. After the war, President Truman spoke of projected losses for the U.S. Army of 0.5 to 1 million. If the origin of these figures is unknown, the order of magnitude does not seem implausible compared to the balance sheet of Okinawa.

Japanese losses

From another perspective, we must not lose sight of the human cost of such a ground operation for the Japanese. In Okinawa, the soldiers of the imperial army had been killed almost to the last, and many civilians were driven to commit suicide, usually under pressure from the army, which itself organized these mass suicides. And to this would have been added the toll of one or two more years of famine and deprivation for the populations.

Prisoners of War

In addition to the arguments previously made, the Americans believed that the atomic bomb would be a solution to force Japan to release the hundreds of thousands of prisoners of war and civilians locked up in Japanese concentration camps scattered throughout Asia.

Corporal Noel Havenborg, American prisoner of war in Luzon, Philippines
Corporal Noel Havenborg, American prisoner of war in Luzon, Philippines

The bomb would also be able to stop Japanese atrocities in China and throughout the Greater East Asia Co-Prosperity Sphere and forced labor for nationals of various Asian countries. The fate of prisoners of war became particularly worrying when the Minister of War ordered the 1st August 1944 to execute Allied prisoners if Japan were to be invaded. It is also likely that Japan would have carried out such punitive actions in the event of a prolonged famine.

In response to the argument of civilian casualties and war crimes caused by the use of atomic weapons, proponents of bombing pointed to Japan’s total non-compliance with the Geneva Protocol, both militarily and civilianly:

  • forced labor of civilians (including women and children), including ten million Chinese civilians conscripted into Manchukuo alone;
  • use of biological weapons and chemical weapons against China, manufactured by Shiro Ishii’s research units (including the plague in Changde, by the admission of Japanese defendants at the Khabarovsk trial);
  • experimentation of bacteriological and chemical weapons by these same units on thousands of human guinea pigs;
  • crimes against prisoners of war and civilian populations.

The surprise attack on Pearl Harbor remained deeply engraved in people’s minds and Japan was considered a deceitful enemy that should not be spared. Father John A. Siemes, professor of philosophy at Tokyo Catholic University and witness to the explosion in Hiroshima, wrote:

“We all discussed together about the ethics behind the use of the bomb. Some classified it as poisonous gases and were against its use on civilian populations. Others believed that in Japan’s all-out war, there was no difference between soldiers and civilians. The bomb itself was an effective force to stop the bloodshed, force Japan to surrender and thus avoid total destruction. It seems logical to me that whoever promotes total war cannot, as a matter of principle, criticize the war against civilian populations.

Of the thirteen American POWs present in Hiroshima on the day of the explosion, only two survived. The U.S. government could afford these few collateral losses. They would probably have been higher if the threat of an atomic attack had been made against Japan before proceeding with the bombing.

The thesis of the strategic posture toward the USSR

The scientists who worked on the project would later testify to the pressure exerted at a high level to finish the bomb on a specific schedule. The latter was closely linked to the actions of the Soviets and their planned entry into the war on August 8. Some historians put forward the thesis of the USSR which was too important and that it was necessary to keep away from Japanese territories.

For them, it is the imminence of the declaration of war of the USSR in Japan planned during the Yalta agreements three months after the capitulation of Germany (so August 9, 1945), which is the determining factor. Indeed, if in Yalta in February 1945, the United States had asked for the help of the USSR to help them finish a war costing in human lives with Japan, six months later, with their new nuclear power they no longer needed to deal with this cumbersome ally to end the conflict and share the profits (zones of influence, military bases, etc.). The United States wanted to prove to Stalin that it was present both in Berlin and in Asia, and that it opposed the development of communism, at least in Japan. This is the thesis defended by Frédéric F. Clairmont in The real reasons for the destruction of Hiroshima.

We can thus consider that these atomic bombings were in a way the harbinger of the Cold War and a show of force on the part of the United States against Stalin. The USSR was subsequently involved in various conflicts in Asia, in particular the Indochina War, the Korean War and the Vietnam War. Japan will avoid the effects of the expansion of Soviet domination in the region thanks to this American tutelage.

Public opinion

Truman was not elected president, he inherited it as vice president upon the death of his predecessor Franklin Delano Roosevelt in April 1945. Truman did not have Roosevelt’s track record or popularity, and in this situation, he might be tempted to make a decision that would quickly strengthen his reputation, especially in the face of the former president’s entourage who did not hold him in high regard.

Other factors of public opinion may have played a role: on the one hand, it was necessary to wash away the affront of Pearl Harbor and justify the two billion dollars invested in the Manhattan Project, on the other hand all means had to be used to shorten the conflict and limit the number of soldiers killed. Each death can be considered the loss of a family member of voters from Truman’s perspective. For historian André Kaspi, a specialist in the United States:

“Everyone will judge in good conscience whether Truman was right or wrong, whether he did whatever was necessary to prevent the last massacre of the war. Provided we do not forget that the Germans and the Japanese themselves had started the conflict, that Allied soldiers were still dying in the early summer of 1945 in the Pacific Islands and China, that the discovery of mass graves, concentration camps and Japanese jungle jails did not incite pity for the vanquished.

The arguments against these bombings

In 1965, historian Gar Alperovitz claimed that Japanese leaders were ready to surrender before the bombings of Hiroshima and Nagasaki, Provided that the life and function of the Japanese emperor are preserved.

Many voices spoke out against the military use of atomic bombs and questioned the necessity of the attacks on Hiroshima and Nagasaki. This decision is still strongly criticized whether in Japan, the United States or the rest of the world. For the philosopher Gunther Anders, humanity, having become capable of destroying itself, the atomic weapon has always been frightening and since the end of the war, several theses tend to suggest that these bombs were not necessary to stop the conflict.

The atomic bomb: a war crime, even a crime against humanity?

Moral aspects

The Manhattan Project was originally intended to thwart Nazi Germany’s nuclear program. Following the defeat of the IIIe Reich, several scientists working on the project felt that the United States should not be the first to use such weapons. Albert Einstein was reluctant to face the bomb and Leó Szilárd, who was largely involved in the development of the bomb, said after the war:

“If the Germans had dropped atomic bombs for us, we would have called the atomic bombing of cities war crimes, condemned the German culprits to death at the Nuremberg trials and hanged them.”

The use of nuclear power for military purposes has been described as “barbaric”, since several hundred thousand civilians had died and the targets were in densely populated cities. During the preparations for the bombing, scientists, including Edward Teller, pointed out that it would be preferable to use the bomb on an uninhabited area or in the sky at night, in order to warn the Japanese.

The inhumanity of the aerial bombardment of civilians had been strongly denounced by Roosevelt on 1st September 1939 during an appeal to European governments:

“The merciless aerial bombardment of civilians in unfortified urban areas, during the hostilities that have raged in different parts of the world in recent years, which has maimed and killed thousands of defenseless women and children, has deeply shocked the conscience of humanity.

If this inhuman barbarity were to be resorted to during the tragic period of confrontation that the world is facing today, hundreds of thousands of innocent people, who are not responsible for the conflict, and who do not even participate in it, would lose their lives.

I therefore address this urgent appeal to every Government which may take part in hostilities to publicly affirm its determination not to commit its armed forces under any circumstances and in any way to the aerial bombardment of civilian populations or unfortified towns, provided that the same rules of war are scrupulously respected by their adversaries.

I demand an immediate response.

It is true that Roosevelt received no sincere answer to this request and that the Germans were the first to use the massive bombing of civilian targets, as early as 1939 with the bombing of Warsaw during the invasion of that country, then with the destruction of Rotterdam and Coventry in 1940.

International Law

Since 1945 the legality of strategic bombing and the use of nuclear weapons has remained a matter of discussion in international law.

It has been argued that the large-scale use of atomic weapons against civilian populations is a war crime and even a crime against humanity.

    • At the time of the bombing, the United States was a signatory to the Hague Conventions of 1899 and 1907. The second prohibits:
      • use of poison or poisoned weapons (Art. 23),
      • attack or bombardment, by any means, of towns, villages, dwellings and undefended buildings (Art. 25).
    • Before the war, the United States had attempted to prohibit the indiscriminate bombing of civilians in a Hague Convention on Customs of War, which it had signed in 1923. However, this convention never entered into force. It provided that:
        <> Aerial bombardment aimed at terrorizing the civilian population, destroying or damaging objects of a non-military nature or injuring non-combatants is prohibited. (Art. 22), <>bombing of cities, towns, villages, dwellings and buildings outside the immediate vicinity of military ground operations is prohibited. In cases where the objectives specified in paragraph 2 are located in such a way that they cannot be bombed without indiscriminate bombing of the civilian population, the aircraft shall refrain from bombing. (Art. 24-3);
    • However, these concepts were partly reflected in the London Accords signed on 8 August 1945, just two days after the bombing of Hiroshima and the day before the bombing of Nagasaki, which aimed to establish an International Military Tribunal and prosecute war crimes and crimes against humanity. They defined war crimes as: “i.e. violations of the laws and customs of war” including “… wanton destruction of towns and villages or devastation not justified by military necessity”. The bombing of densely populated urban areas was therefore part of the debate at the Nuremberg trials, during which US prosecutor Telford Taylor excluded them from the scope of war crimes. These debates proceeded from the terms of Article 6b of the Statute of the International Military Tribunal, adopted by the Allies themselves at the time of these London Agreements;

<> The Fourth Geneva Convention prohibits reprisals against civilians or their property;

    • However, this Convention, signed in 1949, did not apply at the material time (it should be noted, however, that the principle of non-retroactivity of the law was not applied to certain accusations of the Nuremberg trials),

A lack of military justification

Opinions differ on Japan’s ability to withstand attacks. For opponents of atomization, Japan was already deeply weakened by the beginning of 1945 and capitulation was inevitable. General Dwight D. Eisenhower agreed and informed Henry Stimson in July 1945. The highest-ranking officer in the Pacific theater of operations was General Douglas MacArthur. He was not consulted about the bombing but later said that there was no military justification for the attack. The same opinion will be given by Admiral William Leahy, General Carl Spaatz (Commander of the USSAF in the Pacific) and Brigadier General Carter Clarke (Intelligence Officer). Major General Curtis LeMay, Admiral Ernest King (Chief of Naval Operations), Admiral Chester Nimitz (Commander-in-Chief of the Navy in the Pacific) will also express doubts about the atomic bombings.

Eisenhower wrote in his memoir The White House Years:

“In 1945, Secretary of War Stimson, then visiting my headquarters in Germany, informed me that our government was preparing to drop an atomic bomb on Japan. I was one of those who felt that there must be a number of valid reasons to question the wisdom of such an act. During his exposition of the important facts, I was filled with a feeling of sadness and expressed my deep disagreement, first on the basis of my conviction that Japan was already defeated and that the bombing was completely useless, and second because I thought that our country should not shock world opinion by the use of a bomb that I did not think necessary to save the lives of Americans.

Further, he adds:

“MacArthur thought the bombing was completely unnecessary from a military point of view.”

One study, the United States Strategic Bombing Survey, organized by the U.S. military after the surrender, surveyed hundreds of Japanese military and civilian leaders about the bombing; It shows that:

“Based on a thorough study of all the facts and with the support of the testimonies of Japanese leaders still alive, the Study Group is of the opinion that Japan would certainly have capitulated before the December 31, 1945 and perhaps even before the 1st November 1945. Even if the bombs had not been dropped, even if the USSR had not entered the war, and even if no invasion had been planned and envisaged.

The cleavage between the Japanese civil power and the military

The code Purple, name given by the Americans to the machine used by the Japanese to encrypt their messages
The code Purple, name given by the Americans to the machine used by the Japanese to encrypt their messages

Others claim that Japan had tried to surrender at least twice, but the United States refused, insisting that the surrender be unconditional. In fact, while several diplomats favored surrender, Japanese military leaders were preparing the army for a decisive battle. The diplomats thought they could better negotiate the armistice clauses that way. The Americans knew perfectly well the Japanese plans, the encryption used by the Japanese army, the code 97 (or code Purple) had been pierced by the cryptanalysts.

However, even after the attack on Nagasaki, the Supreme Council was still divided, with Korechika Anami, Yoshijiro Umezu and Soemu Toyoda wanting the Japanese authorities to disarm the troops and try the criminals, and insisting on the absence of occupying forces on Japanese soil and the preservation of the imperial regime and the Emperor. Only the direct intervention of the Showa Emperor, who rallied to the supporters of the last demand as the only condition, put an end to the dissensions, without however avoiding a coup attempt that was quickly countered.

Another criticism of the bombing was the speed with which the United States estimated the effects of the Soviet Union’s entry into the war against Japan. Without hindsight on the general situation, the decision to bomb would have been taken hastily. The Americans knew, unlike the Japanese, that the USSR would enter the war three months after victory in Europe. As the USSR could no longer play the role of mediator in the conflict and the world gradually entered the Cold War, it became clear to some Japanese that the best way to keep the emperor on the throne was to accept the conditions set by the opposing side.

With the invasion of the archipelago not imminent, the United States had nothing to lose by waiting a few days to see how the situation would evolve. The decision to capitulate predated successive USSR attacks on Manchuria, Sakhalin Island and the Kuril Islands. Hokkaidō would surely have been invaded by the USSR before the Allies reached Kyūshū. According to this thesis, the purpose of the maneuver was therefore to make the Soviets understand to stay away.

A Japanese study indicates that atomic bombing was not the main cause of surrender. The real reason had its source in the massive victories of the Soviets all around Japan. The Japanese feared a Soviet occupation more than the presence of the Americans on the island. It is clear that both opposing sides had thrown their weight behind the decision, but the Japanese were convinced that Stalin would replace the monarchy with communism, something inconceivable to them.

Other reviews

Others still believe that additional efforts should have been made to reduce the number of victims. In addition to these considerations of casualties, the main purpose of the attack was to have an optimal surprise effect. The decision of the American strategists was clear: no warning should be given before the drop.

After the bombing of Hiroshima, Truman announced that “if they don’t accept our terms now, they can expect a rain of ruins falling from the sky”. On August 8, 1945, leaflets were dropped over Japan and warnings were transmitted via Radio Saipan. The area near Nagasaki did not receive leaflets until August 10, a day after the explosion. The propaganda with information printed on small pieces of paper had been launched in the weeks leading up to the nuclear attack.

Another point of contention concerns the time lapse between the destruction of Hiroshima and that of Nagasaki. Some people argue that the arguments for using the bomb did not apply to Nagasaki. In his semi-autobiographical short story Timequake, Kurt Vonnegut writes that while the bombing of Hiroshima saved the lives of his USAAF comrades, Nagasaki showed how capable the United States was of cruelty without compassion.

In 2014, Lucy van Beek’s documentary “Hiroshima, the true story” supports the thesis of a “clever Western disinformation, having diverted the world from the reality of the facts”, with unpublished archive images, confidential documents, and testimonies of experts, secret agents, and survivors.

From 1945 to the present

Effects on Japanese society

The destruction of Hiroshima is now the subject of an annual commemoration in Japan. However, the survivors of the atomic bombings of Hiroshima and Nagasaki were long mistreated by Japanese society because they symbolized Japan’s defeat. In Japan, debates on the usefulness of the Hiroshima and Nagasaki bombs remain open and the subject is all the more sensitive as the country’s constitutional pacifism is called into question.

Under the U.S. military occupation and until its end in 1952, censorship prevented any media coverage of the bombing and kept Japan away from international debates on nuclear weapons. According to historian John Dower, it was only from 1960 that the first photos of the bombings appeared in Japan.

Fate of the crews of the two bombers

Claude Eatherly, a pilot who witnessed the dropping of the bomb on Hiroshima, refused to be celebrated as a hero, and suffered from various mental illnesses. In 1959, he corresponded with the philosopher Günther Anders, which allowed him to gradually recover from his psychological disorders.

Atomic bombings of Hiroshima and Nagasaki in 1945
Japanese cities bombed
  • Hiroshima
    • dome of Genbaku
    • Shima Hospital
    • Hiroshima Peace Memorial Park
    • bridge Aioi
  • Nagasaki
    • Cathedral of the Immaculate Conception
    • Virgin of Nagasaki
    • Peace Park
Other target cities
  • Kokura
  • Niigata
  • Kyoto
  • Franklin D. Roosevelt
  • Harry S. Truman
  • Hirohito
  • Kantarō Suzuki
Hibakusha (survivors)
  • Hashizume Bun
  • Tamiki Hara
  • Shuntaro Hida
  • Mitoyo Kawate
  • Issey Miyake
  • Takashi Nagai
  • Ken Naganuma
  • Sadako Sasaki
  • Yukio Shimomura
  • Sumiteru Taniguchi
  • Tomotaka Tasaka
  • Tsutomu Yamaguchi
  • Little Boy
  • Fat Man
  • 509th Composite Group
  • Boeing B-29 Superfortress
  • Silverplate
  • Enola Gay
  • Bockscar
  • The Great Artiste
  • Necessary Evil
  • Big Stink
  • Tinian
  • Paul Tibbets
  • Robert A. Lewis
  • Thomas Ferebee
  • Theodore Van Kirk
  • William Sterling Parsons
  • Jacob Beser
  • Morris R. Jeppson
  • George R. Caron
  • Francis Birch
  • Charles Sweeney
  • Frederick Bock
  • Claude Eatherly
  • World War II
  • atomic explosion
  • nuclear weapon
  • bomb A
  • uranium
  • plutonium
  • project Manhattan
  • project Alberta
  • operation Crossroads
  • Pacific War
  • debate on the bombings of Hiroshima and Nagasaki
  • Gen of Hiroshima
  • The Big Secret (1952 film)
  • Hiroshima my love
World War II
  • South Africa
  • Australia
  • Belgium
  • Brazil
  • Canada
  • China
  • Colombia
  • Cuba
  • Denmark
  • USA
  • Ethiopia
  • France
    • France free (from June 1940)
  • Greece
  • India
  • Italy (from September 1943)
  • Luxembourg
  • Mexico
  • New Zealand
  • Norway
  • Netherlands
  • Commonwealth of the Philippines
  • Poland
  • Southern Rhodesia
  • United Kingdom
  • Czechoslovakia
  • Soviet Union
  • Yugoslavia
  • Germany
  • Bulgaria
  • Reorganized National Government of the Republic of China
  • Independent State of Croatia
  • Finland
  • Hungary
  • India
  • Iraq
  • Italy (until 8 September 1943)
  • Italian Social Republic
  • Japan
  • Manchukuo
  • Norway (National Government)
  • Vichy regime
  • Republic of the Philippines
  • Romania
  • Slovakia
  • Thailand
  • Albania
  • Germany
  • Austria
  • Belgium
  • Korea
  • Denmark
  • Estonia
  • France
  • Greece
  • Hong Kong
  • India
  • Italy
  • Japan
  • Jewish
  • Latvia
  • Lithuania
  • Luxembourg
  • Norway
  • Netherlands
  • Philippines
  • Poland
    • Anti-communism
  • Romanian
  • Czechoslovakia
  • Thailand
  • Ukraine
  • Soviet Union
  • Slovakia
  • Vietnam
  • Yugoslavia
  • Invasion of Poland
  • Phoney War
  • Atlantic
  • Changsha
  • Winter War
  • Operation Weserübung
  • Netherlands
  • Belgium
  • France
    • Armistice of 22 June 1940
  • Norway
  • Mediterranean
  • Desert War
  • Baltic States
  • Moldova
  • England
  • British Somaliland
  • Indochina
  • Greece
  • Compass
  • North Africa
  • Caribbean
  • East Africa
  • Yugoslavia
  • Greece
  • Crete
  • Iraq
  • Operation Barbarossa
  • Finland
  • Lithuania
  • Syria and Lebanon
  • Kiev
  • Iran
  • Leningrad
  • Moscow
  • Sevastopol
  • Pearl Harbor
  • Hong Kong
  • Philippines
  • Changsha
  • Philippines
  • British Malaysia
  • Borneo (1941-1942)
  • Burma (1942)
  • Changsha
  • Java Sea
  • Coral Sea
  • Gazala
  • Midway
  • Fall Blau
  • Stalingrad
  • Dieppe
  • Kiev
  • El Alamein
  • Guadalcanal
  • Torch
  • Burma
  • Solomon Islands
  • Tunisia
  • Kursk
  • Italy
    • Armistice of Cassibile
  • Smolensk
  • Dnieper
  • Gilbert and Marshall Islands
  • Changde
  • Monte Cassino/Shingle
  • Narva
  • Cherkasy
  • Storm
  • Ichi-Go
  • Operation Neptune
  • Normandie
  • Mariana Islands and Palau
  • Bagration
  • Lvov-Sandomir
  • Warsaw
  • Jassy-Kishinev
  • Paris
  • Provence
  • Siegfried Line
  • Belgrade
  • Gothic line
  • Market Garden
  • Tallinn
  • Crossbow
  • Combined bombing offensive
  • Lapland
  • Budapest
  • Leyte
  • Ardennes
    • Operation Bodenplatte
  • Philippines (1944-1945)
  • Burma (1944-1945)
  • Budapest
  • Vistula-Oder
  • Siege of Posen (1945)
  • Iwo Jima
  • German Campaign (1945)
  • Okinawa
  • Italy (1945 offensive)
  • Berlin
  • Czechoslovakia
  • Chinese reconquest of 1945
  • Surrender of Germany
  • Manchuria
  • Manila
  • Borneo
  • Atomic bombings
  • Sakhalin
  • Kuril Islands
  • Surrender of Japan
  • Aviation
  • Bomber stream
  • Battle of the Beams
  • Strategic bombing
  • Blitzkrieg
  • Military equipment
  • Electronic warfare equipment
  • Purge at the Liberation in France
  • Lend-Lease
  • Manhattan Project
  • Spoliation of works of art
  • Technology and logistics
    • Asia and the Pacific
      • China
      • Southeast Asia
      • Pacific
      • North and Central Pacific
      • South West Pacific
      • Indian Ocean
    • Europe
      • Western Front
      • Eastern Front
  • Mediterranean and Middle East
      • North Africa
      • East Africa
      • Italy
    • West Africa
  • Atlantic
    • chronology
  • Americas
  • Expulsion of the Germans
  • Operation Paperclip
  • Operation Keelhaul
  • Occupation of Germany
  • Occupation of Austria
  • Soviet occupations
    • Romania
    • Poland
    • Hungary
    • Baltic States
  • Occupation of Japan
  • Indochina War
  • Indonesian National Revolution
  • Manhattan Project
  • Decolonization
  • Cold War
  • Allied War Crimes
  • War crimes of the Wehrmacht (Holocaust)
    • Nuremberg Trials
  • Nazi War Crimes in the Soviet Union (Hungerplan)
  • War crimes in occupied Poland
  • Einsatzgruppen
  • War crimes of Italy
  • War crimes of Japan Shōwa (Unit 731)
    • Tokyo Trial
  • War crimes of the USSR
  • Genocide against Serbs in the Independent State of Croatia
  • Evacuations and expulsions of populations
  • German military brothels
  • Bordels of German camps
  • Rape during the occupation of Japan
  • Nanking Massacre
  • Rape during the second invasion of Poland by the Red Army
  • Rape during the release of the France
  • Rape during the occupation of Germany
  • Rape as a weapon of genocide
  • German prisoners in the Soviet Union
  • German prisoners in the United States
  • Belgian prisoners of war
  • French prisoners of war
  • Japanese prisoners in the Soviet Union
  • Nazi crimes against Soviet prisoners of war
  • Italian prisoners in the Soviet Union
  • Forced labor under Nazi rule
    • Albania
    • Germany
    • Austria
    • Belgium
    • Belarus
    • Croatia
    • Estonia
    • France
    • Greece
      • in a Bulgarian-occupied zone
    • Hungary
    • Italy
    • Latvia
    • Lithuania
    • Luxembourg
    • Norway
    • Netherlands
    • Poland
    • Romania
    • Russia
    • Serbia
  • Czechoslovakia
    • Bohemia-Moravia
    • Sudetenland
    • Slovakia
  • Ukraine

References (sources)