Atomic bombings of Hiroshima and Nagasaki
From Wikipedia, the free encyclopedia
| ||
| ||
Despite six months of intense strategic fire-bombing of 67 Japanese cities, the Japanese government ignored an ultimatum given by the Potsdam Declaration. By executive order of President Harry S. Truman, the U.S. dropped the nuclear weapon "Little Boy" on the city of Hiroshima on Monday, August 6, 1945,[1][2] followed by the detonation of "Fat Man" over Nagasaki on August 9. These two events are the only active deployments of nuclear weapons in war.[3] The target of Hiroshima was a city of considerable military importance, containing Japan's Second Army Headquarters, as well as being a communications center and storage depot.[4]
Within the first two to four months of the bombings, the acute effects killed 90,000–166,000 people in Hiroshima and 60,000–80,000 in Nagasaki,[5] with roughly half of the deaths in each city occurring on the first day. The Hiroshima prefectural health department estimates that, of the people who died on the day of the explosion, 60% died from flash or flame burns, 30% from falling debris and 10% from other causes. During the following months, large numbers died from the effect of burns, radiation sickness, and other injuries, compounded by illness. In a more plausible estimate of the total immediate and short term cause of death, 15–20% died from radiation sickness, 20–30% from flash burns, and 50–60% from other injuries, compounded by illness.[6] In both cities, most of the dead were civilians.[7][8][9]
Six days after the detonation over Nagasaki, on August 15, Japan announced its surrender to the Allied Powers, signing the Instrument of Surrender on September 2, officially ending the Pacific War and therefore World War II. Germany had signed its Instrument of Surrender on May 7, ending the war in Europe. The bombings led, in part, to post-war Japan adopting Three Non-Nuclear Principles, forbidding the nation from nuclear armament.[10] The role of the bombings in Japan's surrender and the U.S.'s ethical justification for them, as well as their strategical importance, is still debated.[11][12]
The Manhattan Project
Main article: Manhattan Project
The U.S., in collaboration with the United Kingdom and Canada, with their respective secret projects Tube Alloys and Chalk River Laboratories,[13][14] designed and built the first atomic bombs under what was called the Manhattan Project. The scientific research was directed by American physicist J. Robert Oppenheimer and the overall project was under the authority of General Leslie Groves, of the U.S. Army Corps of Engineers. The Hiroshima bomb, a gun-type bomb called "Little Boy," was made with uranium-235, a rare isotope of uranium extracted in giant factories in Oak Ridge, Tennessee. The atomic bomb was first tested at Trinity Site, on July 16, 1945, near Alamogordo, New Mexico. The test weapon, "the gadget," and the Nagasaki bomb, "Fat Man," were both implosion-type devices made primarily of plutonium-239, a synthetic element created in nuclear reactors at Hanford, Washington.[15] The Manhattan Project had evolved out of earlier endeavors, beginning in 1939, to research atomic weapons, undertaking originally because of fear that Nazi Germany would develop them first. By early 1945, these fears had been proven false, and attentions had turned towards the possible use of the weapons against the Japanese.Choice of targets
- The target was larger than three miles in diameter and was an important target in a large urban area.
- The blast would create effective damage.
- The target was unlikely to be attacked by August 1945. "Any small and strictly military objective should be located in a much larger area subject to blast damage in order to avoid undue risks of the weapon being lost due to bad placing of the bomb."[16]
During World War II, Edwin O. Reischauer was the Japan expert for the U.S. Army Intelligence Service, in which role he is incorrectly said to have prevented the bombing of Kyoto.[17] In his autobiography, Reischauer specifically refuted the validity of this claim:
- "...the only person deserving credit for saving Kyoto from destruction is Henry L. Stimson, the Secretary of War at the time, who had known and admired Kyoto ever since his honeymoon there several decades earlier."[18]
The Potsdam ultimatum
On July 26, Truman and other allied leaders issued the Potsdam Declaration outlining terms of surrender for Japan. It was presented as an ultimatum and stated that without a surrender, the Allies would attack Japan, resulting in "the inevitable and complete destruction of the Japanese armed forces and just as inevitably the utter devastation of the Japanese homeland". The atomic bomb was not mentioned in the communique. On July 28, Japanese papers reported that the declaration had been rejected by the Japanese government. That afternoon, Prime Minister Kantaro Suzuki declared at a press conference that the Potsdam Declaration was no more than a rehash (yakinaoshi) of the Cairo Declaration and that the government intended to ignore it (mokusatsu lit. "kill by silence").[19] The statement was taken by both Japanese and foreign papers as a clear rejection of the declaration. Emperor Hirohito, who was waiting for a Soviet reply to noncommittal Japanese peace feelers, made no move to change the government position.[20] On July 31, he made clear to his advisor Kōichi Kido that the Imperial Regalia of Japan had to be defended at all costs.[21]In early July, on his way to Potsdam, Truman had re-examined the decision to use the bomb. In the end, Truman made the decision to drop the atomic bombs on Japan. His stated intention in ordering the bombings was to bring about a quick resolution of the war by inflicting destruction and instilling fear of further destruction in sufficient strength to cause Japan to surrender.[22]
Hiroshima
Hiroshima during World War II
The center of the city contained several reinforced concrete buildings and lighter structures. Outside the center, the area was congested by a dense collection of small wooden workshops set among Japanese houses. A few larger industrial plants lay near the outskirts of the city. The houses were constructed of wood with tile roofs, and many of the industrial buildings were also built around wood frames. The city as a whole was highly susceptible to fire damage.
The population of Hiroshima had reached a peak of over 381,000 earlier in the war, but prior to the atomic bombing the population had steadily decreased because of a systematic evacuation ordered by the Japanese government. At the time of the attack, the population was approximately 340,000–350,000.[5] Because official documents were burned, the exact population is uncertain.
The bombing
For the composition of the USAAF mission, see 509th Operations Group#Components.
Hiroshima was the primary target of the first nuclear bombing mission on August 6, with Kokura and Nagasaki being alternative targets. August 6 was chosen because clouds had previously obscured the target. The 393d Bombardment Squadron B-29 Enola Gay, piloted and commanded by 509th Composite Group commander Colonel Paul Tibbets, was launched from North Field airbase on Tinian in the West Pacific, about six hours flight time from Japan. The Enola Gay (named after Colonel Tibbets' mother) was accompanied by two other B-29s. The Great Artiste, commanded by Major Charles W. Sweeney, carried instrumentation; and a then-nameless aircraft later called Necessary Evil (the photography aircraft) was commanded by Captain George Marquardt.[25]After leaving Tinian the aircraft made their way separately to Iwo Jima where they rendezvoused at 2,440 meters (8,010 ft) and set course for Japan. The aircraft arrived over the target in clear visibility at 9,855 meters (32,333 ft). During the journey, Navy Captain William Parsons had armed the bomb, which had been left unarmed to minimize the risks during takeoff. His assistant, 2nd Lt. Morris Jeppson, removed the safety devices 30 minutes before reaching the target area.[26]
The release at 08:15 (Hiroshima time) went as planned, and the gravity bomb known as "Little Boy", a gun-type fission weapon with 60 kilograms (130 lb) of uranium-235, took 43 seconds to fall from the aircraft flying at 31,060 feet (9,470 m)[29] to the predetermined detonation height about 1,900 feet (580 m) above the city. The Enola Gay had traveled 11.5 miles away before it felt the shock waves from the blast.[30]
Due to crosswind, it missed the aiming point, the Aioi Bridge, by almost 800 feet (240 m) and detonated directly over Shima Surgical Clinic.[31] It created a blast equivalent to about 13 kilotons of TNT (54 TJ). (The U-235 weapon was considered very inefficient, with only 1.38% of its material fissioning.)[32] The radius of total destruction was about one mile (1.6 km), with resulting fires across 4.4 square miles (11 km2).[33] Americans estimated that 4.7 square miles (12 km2) of the city were destroyed. Japanese officials determined that 69% of Hiroshima's buildings were destroyed and another 6–7% damaged.[6]
70,000–80,000 people, or some 30%[34] of the population of Hiroshima were killed immediately, and another 70,000 injured.[35] Over 90% of the doctors and 93% of the nurses in Hiroshima were killed or injured—most had been in the downtown area which received the greatest damage.[36]
Although the U.S. had previously dropped leaflets warning civilians of air raids on 35 Japanese cities, including Hiroshima and Nagasaki,[37] the residents of Hiroshima were given no notice of the atomic bomb.[38][39][40]
Japanese realization of the bombing
 |  | |
| Hiroshima before the bombing. | Hiroshima after the bombing. |
Military bases repeatedly tried to call the Army Control Station in Hiroshima. The complete silence from that city puzzled the men at headquarters; they knew that no large enemy raid had occurred and that no sizeable store of explosives was in Hiroshima at that time. A young officer of the Japanese General Staff was instructed to fly immediately to Hiroshima, to land, survey the damage, and return to Tokyo with reliable information for the staff. It was generally felt at headquarters that nothing serious had taken place and that the explosion was just a rumor.
The staff officer went to the airport and took off for the southwest. After flying for about three hours, while still nearly 100 miles (160 km) from Hiroshima, he and his pilot saw a great cloud of smoke from the bomb. In the bright afternoon, the remains of Hiroshima were burning. Their plane soon reached the city, around which they circled in disbelief. A great scar on the land still burning and covered by a heavy cloud of smoke was all that was left. They landed south of the city, and the staff officer, after reporting to Tokyo, immediately began to organize relief measures.
By August 8, 1945, newspapers in the U.S. were reporting that broadcasts from Radio Tokyo had described the destruction observed in Hiroshima. "Practically all living things, human and animal, were literally seared to death," Japanese radio announcers said in a broadcast received by Allied sources.[42]
Post-attack casualties
Survival of some structures
Events of August 7–9
 | |
| Problems listening to this file? See media help. | |
If they do not now accept our terms, they may expect a rain of ruin from the air, the like of which has never been seen on this earth. Behind this air attack will follow sea and land forces in such numbers and power as they have not yet seen and with the fighting skill of which they are already well aware.[55]The Japanese government still did not react to the Potsdam Declaration. Emperor Hirohito, the government, and the war council were considering four conditions for surrender: the preservation of the kokutai (Imperial institution and national polity), assumption by the Imperial Headquarters of responsibility for disarmament and demobilization, no occupation of the Japanese Home Islands, Korea, or Formosa, and delegation of the punishment of war criminals to the Japanese government.[56]
The Soviet Foreign Minister Vyacheslav Molotov had informed Tokyo of the Soviet Union's unilateral abrogation of the Soviet–Japanese Neutrality Pact on April 5. At two minutes past midnight on August 9, Tokyo time, Soviet infantry, armor, and air forces had launched the Manchurian Strategic Offensive Operation. Four hours later, word reached Tokyo that the Soviet Union had declared war on Japan. The senior leadership of the Japanese Army began preparations to impose martial law on the nation, with the support of Minister of War Korechika Anami, in order to stop anyone attempting to make peace.
Responsibility for the timing of the second bombing was delegated to Colonel Tibbets as commander of the 509th Composite Group on Tinian. Scheduled for August 11 against Kokura, the raid was moved earlier by two days to avoid a five day period of bad weather forecast to begin on August 10.[57] Three bomb pre-assemblies had been transported to Tinian, labeled F-31, F-32, and F-33 on their exteriors. On August 8, a dress rehearsal was conducted off Tinian by Maj. Charles Sweeney using Bockscar as the drop airplane. Assembly F-33 was expended testing the components and F-31 was designated for the August 9 mission.[58]
Nagasaki
"I realize the tragic significance of the atomic bomb... It is an awful responsibility which has come to us... We thank God that it has come to us, instead of to our enemies; and we pray that He may guide us to use it in His ways and for His purposes."
—President Harry Truman, August 9, 1945 [59]
Nagasaki during World War II
The city of Nagasaki had been one of the largest sea ports in southern Japan and was of great wartime importance because of its wide-ranging industrial activity, including the production of ordnance, ships, military equipment, and other war materials.
In contrast to many modern aspects of Hiroshima, almost all of the buildings were of old-fashioned Japanese construction, consisting of wood or wood-frame buildings with wood walls (with or without plaster) and tile roofs. Many of the smaller industries and business establishments were also situated in buildings of wood or other materials not designed to withstand explosions. Nagasaki had been permitted to grow for many years without conforming to any definite city zoning plan; residences were erected adjacent to factory buildings and to each other almost as closely as possible throughout the entire industrial valley.
Nagasaki had never been subjected to large-scale bombing prior to the explosion of a nuclear weapon there. On August 1, 1945, however, a number of conventional high-explosive bombs were dropped on the city. A few hit in the shipyards and dock areas in the southwest portion of the city, several hit the Mitsubishi Steel and Arms Works, and six bombs landed at the Nagasaki Medical School and Hospital, with three direct hits on buildings there. While the damage from these bombs was relatively small, it created considerable concern in Nagasaki and many people—principally school children—were evacuated to rural areas for safety, thus reducing the population in the city at the time of the nuclear attack.
To the north of Nagasaki there was a camp holding British Commonwealth prisoners of war, some of whom were working in the coal mines and only found out about the bombing when they came to the surface.
The bombing
For the composition of the USAAF mission, see 509th Operations Group#Components.
On the morning of August 9, 1945, the U.S. B-29 Superfortress Bockscar, flown by the crew of 393rd Squadron commander Major Charles W. Sweeney, carried the nuclear bomb code-named "Fat Man", with Kokura as the primary target and Nagasaki the secondary target. The mission plan for the second attack was nearly identical to that of the Hiroshima mission, with two B-29s flying an hour ahead as weather scouts and two additional B-29s in Sweeney's flight for instrumentation and photographic support of the mission. Sweeney took off with his weapon already armed but with the electrical safety plugs still engaged.[60]Observers aboard the weather planes reported both targets clear. When Sweeney's aircraft arrived at the assembly point for his flight off the coast of Japan, the third plane, Big Stink, flown by the group's Operations Officer, Lt. Col. James I. Hopkins, Jr. failed to make the rendezvous. Bockscar and the instrumentation plane circled for 40 minutes without locating Hopkins. Already 30 minutes behind schedule, Sweeney decided to fly on without Hopkins.[60]
At about 07:50 Japanese time, an air raid alert was sounded in Nagasaki, but the "all clear" signal was given at 08:30. When only two B-29 Superfortresses were sighted at 10:53, the Japanese apparently assumed that the planes were only on reconnaissance and no further alarm was given.
A few minutes later at 11:00, The Great Artiste, the support B-29 flown by Captain Frederick C. Bock, dropped instruments attached to three parachutes. These instruments also contained an unsigned letter to Professor Ryokichi Sagane, a nuclear physicist at the University of Tokyo who studied with three of the scientists responsible for the atomic bomb at the University of California, Berkeley, urging him to tell the public about the danger involved with these weapons of mass destruction. The messages were found by military authorities but not turned over to Sagane until a month later.[62] In 1949, one of the authors of the letter, Luis Alvarez, met with Sagane and signed the document.[63]
Casualty estimates for immediate deaths range from 40,000 to 75,000.[66][67][68] Total deaths by the end of 1945 may have reached 80,000.[5] At least eight known POWs died from the bombing and as many as 13 POWs may have died:
- One British Commonwealth citizen[69][70][71][72][73] died in the bombing.
- Seven Dutch POWs (two names known)[74] died in the bombing.
- At least two POWs reportedly died postwar from cancer thought to have been caused by the atomic bomb.[75][76]
One American POW, Joe Kieyoomia, was in Nagasaki at the time of the bombing but survived, reportedly having been shielded from the effects of the bomb by the concrete walls of his cell.[79]
An unknown number of survivors from the Hiroshima bombing had made their way to Nagasaki, where they were bombed again.[80][81]
The Mitsubishi-Urakami Ordnance Works, the factory that manufactured the type 91 torpedoes released in Pearl Harbor, was destroyed in the blast.[82]
There is also a peace monument and Bell of Nagasaki in the Kokura.[83]
Plans for more atomic attacks on Japan
The U.S. expected to have another atomic bomb ready for use in the third week of August, with three more in September and a further three in October.[84] On August 10, Major General Leslie Groves, military director of the Manhattan Project, sent a memorandum to General of the Army George Marshall, Army Chief of Staff, in which he wrote that "the next bomb . . should be ready for delivery on the first suitable weather after 17 or August 18." On the same day, Marshall endorsed the memo with the comment, "It is not to be released over Japan without express authority from the President."[84] There was already discussion in the War Department about conserving the bombs in production until Operation Downfall, the projected invasion of Japan, had begun. "The problem now [August 13] is whether or not, assuming the Japanese do not capitulate, to continue dropping them every time one is made and shipped out there or whether to hold them . . . and then pour them all on in a reasonably short time. Not all in one day, but over a short period. And that also takes into consideration the target that we are after. In other words, should we not concentrate on targets that will be of the greatest assistance to an invasion rather than industry, morale, psychology, and the like? Nearer the tactical use rather than other use."[84]Surrender of Japan and subsequent occupation
Main articles: Surrender of Japan and Occupation of Japan
Until August 9, the war council had still insisted on its four conditions for surrender. On that day Hirohito ordered Kido to "quickly control the situation ... because the Soviet Union has declared war against us." He then held an Imperial conference during which he authorized minister Tōgō to notify the Allies that Japan would accept their terms on one condition, that the declaration "does not compromise any demand which prejudices the prerogatives of His Majesty as a Sovereign ruler."[85]On August 10, the Japanese government presented a letter of protest for the atomic bombings to the government of the United States via the government of Switzerland.[86] On August 12, the Emperor informed the imperial family of his decision to surrender. One of his uncles, Prince Asaka, then asked whether the war would be continued if the kokutai could not be preserved. Hirohito simply replied "of course."[87] As the Allied terms seemed to leave intact the principle of the preservation of the Throne, Hirohito recorded on August 14 his capitulation announcement which was broadcast to the Japanese nation the next day despite a short rebellion by militarists opposed to the surrender.
In his declaration, Hirohito referred to the atomic bombings:
| “ | Moreover, the enemy now possesses a new and terrible weapon with the power to destroy many innocent lives and do incalculable damage. Should we continue to fight, not only would it result in an ultimate collapse and obliteration of the Japanese nation, but also it would lead to the total extinction of human civilization. Such being the case, how are We to save the millions of Our subjects, or to atone Ourselves before the hallowed spirits of Our Imperial Ancestors? This is the reason why We have ordered the acceptance of the provisions of the Joint Declaration of the Powers. | ” |
During the year after the bombing, approximately 40,000 U.S. troops occupied Hiroshima, while Nagasaki was occupied by 27,000 troops.
Depiction and public response
News of the atomic bombing were greeted enthusiastically in the U.S.; a poll in Fortune magazine in late 1945 showed a significant minority of Americans wishing that more atomic bombs could have been dropped on Japan.[91] The initial positive response was supported by the imagery presented to the public (mainly the powerful mushroom cloud) and the censorship of photographs that showed corpses incinerated by the blast as well as photos of maimed survivors.[91] As an example, a member of the U.S. Strategic Bombing Survey, Lieutenant Daniel McGovern, used a film crew to document the results. The film crew's work resulted in a three-hour documentary entitled The Effects of the Atomic Bombs Against Hiroshima and Nagasaki. The documentary included images from hospitals showing the human effects of the bomb; it showed burned out buildings and cars, and rows of skulls and bones on the ground. When sent to the U.S., it was mentioned widely in the U.S. press, then quietly suppressed and never shown. It was classified "top secret" for the next 22 years.[92] During this time in America, it was a common practice for editors to keep graphic images of death out of films, magazines and newspapers.
Imagery of the atomic bombings was suppressed in Japan during the occupation[93] although some Japanese magazines had managed to publish images before the Allied occupation troops took control. The Allied occupation forces enforced censorship on anything "that might, directly or by inference, disturb public tranquility", and pictures of the effects on people on the ground were deemed inflammatory. A likely reason for the banning was that the images depicting burn victims and funeral pyres evoked similarities to the widely circulated images taken in liberated Nazi concentration camps.[94]
Atomic Bomb Casualty Commission
In the spring of 1948, the Atomic Bomb Casualty Commission (ABCC) was established in accordance with a presidential directive from Harry S. Truman to the National Academy of Sciences-National Research Council to conduct investigations of the late effects of radiation among the survivors in Hiroshima and Nagasaki.Among the casualties were found many unintended victims, including Allied POWs, Korean and Chinese laborers, students from Malaya on scholarships, and some 3,200 Japanese American citizens.[95]
One of the early studies conducted by the ABCC was on the outcome of pregnancies occurring in Hiroshima and Nagasaki, and in a control city, Kure located 18 miles (29 km) south from Hiroshima, in order to discern the conditions and outcomes related to radiation exposure. One author has claimed that the ABCC refused to provide medical treatment to the survivors for better research results.[96] In 1975, the Radiation Effects Research Foundation was created to assume the responsibilities of ABCC.[97]
The Hibakusha
Main article: Hibakusha
Korean survivors
Double survivors
On March 24, 2009, the Japanese government officially recognized Tsutomu Yamaguchi (1916–2010) as a double hibakusha. He was confirmed to be 3 kilometers from ground zero in Hiroshima on a business trip when Little Boy was detonated. He was seriously burnt on his left side and spent the night in Hiroshima. He arrived at his home city of Nagasaki on August 8, a day before Fat Man was dropped, and he was exposed to residual radiation while searching for his relatives. He was the first officially recognised survivor of both bombings.[105] Tsutomu Yamaguchi died on January 4, 2010, after a battle with stomach cancer at the age of 93.[106]Other people also suffered the effects of both bombings, known as nijū hibakusha in Japan. The 2006 documentary Twice Survived: The Doubly Atomic Bombed of Hiroshima and Nagasaki documented 165 nijū hibakusha, was screened at the United Nations.[107]
Debate over bombings
Further information: Operation Downfall
| “ | The atomic bomb was more than a weapon of terrible destruction; it was a psychological weapon. | ” |
Supporters of the bombings generally assert that they caused the Japanese surrender, preventing massive casualties on both sides in the planned invasion of Japan: Kyūshū was to be invaded in October 1945 and Honshū five months later. Some estimate Allied forces would have suffered 1 million casualties in such a scenario, while Japanese casualties would have been in the millions.[109] Although thousands of Japanese were taken prisoner,[110] most fought until they were killed or committed suicide.[111] One scholar estimated that kamikaze attacks could have sunk or damaged a full third of the invasion armada destined for Kyūshū.[110] Others who oppose the bombings argue that it was simply an extension of the already fierce conventional bombing campaign[112] and, therefore, militarily unnecessary,[12] inherently immoral, a war crime, or a form of state terrorism.[113]
0 Comments