Atomic Bombings of Hiroshima and Nagasaki | World War II

The US launched two nuclear weapons over Hiroshima and Nagasaki on August 6 and 9, 1945. Between 129,000 and 226,000 persons died in the two attacks, most of them civilians. In the last year of WWII, the Allies planned a costly invasion of Japan. An earlier conventional and firebombing campaign damaged 67 Japanese cities. After Germany capitulated on May 8, 1945, the Allies focused only on the Pacific War. A plutonium implosion-type nuclear weapon, "Fat Man," was developed by the Allies' Manhattan Project in July 1945. It was trained and equipped with the specialist Silverplate version of the Boeing B-29 Superfortress and sent to Tinian in the Mariana Islands. According to the Allies' Potsdam Declaration on July 26, 1945, "prompt and total destruction" was the alternative to an unconditional surrender. Japan did not respond.

The bombing of Hiroshima, Kokura, Niigata, and Nagasaki was ordered by General Thomas Handy, acting Chief of Staff of the United States Military, on July 25. These targets were picked because they were large cities with military facilities. Prime Minister Suzuki underlined the Japanese government's commitment to defy the Allies' demands and fight on August 6. Three days later, Nagasaki got a Fat Man. Two to four months after the bombings, between 90,000 and 146,000 people were killed in Hiroshima and amid 39,000 and 80,000 in Nagasaki. Throughout the months that followed, many people died from burns, radiation sickness, and injuries, in addition to illness and starvation. Despite a significant military presence, most of the dead were civilians.

Six days later the Soviet Union announced war and bombed Nagasaki, Japan surrendered to the Allies on August 15. On September 2, Japan surrendered, thereby ending the war. Scholars have carefully analyzed the repercussions of the bombings on later world history and popular culture, and the ethical and legal rationale for the bombings is still debated. Critics contend that the Japanese government might have been forced to surrender without using atomic weapons, citing the moral and ethical consequences of nuclear weapons and the killing of civilians.

Pacific War

The Pacific War among Japan and the Associates reached its fourth year in 1945. Most Japanese military forces fought valiantly, ensuring an expensive Allied triumph. The US suffered 1.25 million war casualties in WWII, including killed and wounded. Nearly a million deaths occurred in the war's final year, June 1944–June 1945. The German Ardennes Offensive caused 88,000 American military deaths in December 1944. America's human resources were depleting. Groups like farm labourers were strengthened, and women were considered for drafting. The public was becoming tired of war and demanding that long-serving veterans be sent home. In the Pacific, the Allies regained Burma and invaded Borneo. Offences were launched against Japanese soldiers in Bougainville, New Guinea, and the Philippines.

U.S. soldiers landed on Okinawa in April 1945, and fierce fighting raged until June. Then, from five to one in the Philippines to two to one on Okinawa, the ratio of Japanese to American casualties fell. While some Japanese soldiers were captured, most were slain or committed suicide. As a result, nearly all 21,000 Iwo Jima defenders died. From April to June 1945, 94 per cent of the 117,000 Okinawan and Japanese troops defending Okinawa were dead.

The Japanese people's situation deteriorated as the Allies marched nearer Japan. A drop from 5,250,000 gross tons in 1941 to 1,560,000 gross tons in March 1945 and 557,000 gross tons in August 1945. After mid-1944, the Japanese war economy collapsed due to a lack of raw resources. The civilian economy had deteriorated steadily throughout the war and reached a crisis point in mid-1945. The loss of ships damaged the fishing fleet, and the catch in 1945 was only 22% of 1941. The 1945 rice crop was the worst since 1909, causing widespread starvation. The US industrial output dominated Japan's. During the war, the US produced about 100,000 aircraft per year by 1943, compared to 70,000 by Japan. Prince Fumimaro Konoe recommended Emperor Hirohito to surrender in February 1945.

Preparations to Invade Japan

Operation Downfall, the Allied invasion of Japan, was planned even before Nazi Germany surrendered on May 8, 1945. Operation Olympic and Operation Coronet were the two sections. Olympic began in October 1945 with a series of landings by the US Sixth Army to conquer the southern section of the Japanese island of Kysh. In March 1946, the US First, Eighth, and Tenth Armies, along with a Commonwealth Corps of Australian, British, and Canadian divisions, captured the Kant Plain near Tokyo on the significant Japanese island of Honsh. The target date was established to allow for Olympic's completion, European army redeployment, and the Japanese winter. Because of Japan's geography, the Japanese could forecast the Allied invasion intentions and alter their defensive plan, Operation Ketsug. The Japanese planned a full-scale defence of Kysh, leaving little room for future defence operations. Forty-five new divisions were formed between February and May 1945, replacing four veteran divisions from the Kwantung Army in Manchuria. Most were stationary coastal defence units, while 16 were excellent mobile divisions. The Japanese Army had 2.3 million troops and a citizen militia of 28 million men and women to defend the home islands. The predicted casualty rate was exceedingly high. Vice Admiral Takijirnishi of the Imperial Japanese Navy General Staff anticipated 20 million Japanese deaths.

On 15 June 1945, the Joint War Plans Committee predicted that the Olympics would result in 130,000 to 220,000 US losses, with 25,000 to 46,000 US killed. The assessment acknowledged Japan's insufficient defences due to the efficient sea blockade and the American firebombing campaign. General George Marshall, US Military Chief of Staff, and General Douglas MacArthur, US Army Commander in Chief in the Pacific, signed paperwork approving the Joint War Plans Committee estimate. However, the Japanese buildup was tracked by Ultra intelligence, alarming the Americans. Mr Stimson was concerned enough about the high American estimates to commission his investigation by Quincy Wright and William Shockley. Wright and Shockley interviewed Colonels James McCormack and Dean Rusk and studied Michael E. DeBakey and Gilbert Beebe's fatality projections. Wright and Shockley projected that the invading Allies would lose between 1.7 and 4 million soldiers, with 400,000 to 800,000 dying, while the Japanese would lose between 5 and 10 million. Marshall considered using an "affordable and certain to save American lives" weapon: poison gas. MacArthur confirmed that Chemical Warfare Service units were trained in phosgene, mustard gas, tear gas, and cyanogen chloride. Biological weapons against Japan were also considered.

Air Raids on Japan

The US had planned an air campaign against Japan before the Pacific War, but the conquest of Allied bases in the western Pacific delayed the attack until mid-1944 when the long-range Boeing B-29 Superfortress was ready for battle. In Operation Matterhorn, B-29s from India staged strikes against critical targets in Japan from bases around Chengdu, China. However, this endeavour failed to meet its strategic goals due to logistical issues, mechanical issues with the bomber, the vulnerability of Chinese staging locations, and the great range required to reach critical Japanese cities. BG Haywood S. Hansell assessed that Guam, Tinian, and Saipan would be better B-29 bases, but they were under Japanese control.

For adapting to the air war, the islands were conquered between June and August 1944. In October 1944, B-29 operations began from the Marianas. Cargo ships easily restocked these bases. It began attacking Japan on November 18, 1944. Early tries to bomb Japan from the Marianas was unsuccessful to like the B-29s from China did. Hansell continued to use so-called high-altitude precision bombing on important industry and transportation networks, even after these techniques died. These efforts failed because of logistical issues, technical issues with the new and advanced aircraft, adverse weather, and enemy action.

Major General Curtis LeMay took command in January 1945 and used the same precision bombing techniques, with similar results. However, most Japanese manufacturing is done in small businesses and private houses. Under force from USAAF headquarters in Washington, LeMay shifted strategies and decided that low-level incendiary strikes against Japanese cities were the only option to destroy their industrial capacity. With most strategic bombing during WWII, the goal was to destroy the enemy's military industries, kill or disable civilian employees, and destroy civilian morale.

In six months, LeMay's XXI Bomber Command firebombed 67 Japanese cities. Over 100,000 individuals were killed in the firebombing of Tokyo on March 9–10, codenamed Operation Meetinghouse. The war's bloodiest bombing operation, with 20 B-29s downed by flak and fighters. By May, 75% of dropped bombs were incendiaries meant to burn Japan's "paper cities". Japanese cities were devastated by mid-June. Because Okinawa was no longer fighting, airfields were closer to the Japanese mainland, allowing the bombing campaign to escalate. Allied planes from the Ryukyu Islands and ships repeatedly hit targets in Japan during 1945. Firebombing shifted to 60,000-350,000-person cities. Yuki Tanaka claims the US firebombed over a hundred Japanese cities. These raids wreaked havoc

The Japanese military and civil defence preparedness failed to stop the Allied attacks. High-altitude bombers posed a challenge to Japanese fighters and anti-aircraft guns. Japanese interceptors had to face American fighter escorts from Iwo Jima and Okinawa from April 1945. The Imperial Japanese Military and Navy Air Services stopped intercepting airstrikes that month to save fighter aircraft for the coming invasion. To save fuel, the Japanese only occasionally scrambled aircraft to intercept B-29s flying reconnaissance missions over the country by mid-1945. In April, May, and June 1945, the home islands consumed 604,000 US barrels (72,000,000 l). Despite the Japanese military's decision to commence attacks on Allied bombers in late June, too few operational fighters were available to stop the Allied air attacks.

Atomic Bomb Development

In 1938, German chemists Otto Hahn and Fritz Strassmann discovered nuclear fission and was theoretically explained by Lise Meitner and Otto Frisch. However, the Einstein-Szilard letter voiced concern that a German atomic bomb programme might develop first, especially among experts fleeing Nazi Germany and other fascist countries. It sparked an early US investigation in late 1939. The British MAUD Committee reported in late 1941 that instead of tons of natural uranium and a neutron moderator like heavy water, 5 to 10 kilos of isotopically enriched uranium-235 could be used for a bomb.

The Quebec Agreement united the British and Canadian nuclear weapons projects, Tube Alloys and the Montreal Laboratory, with the Manhattan Project. Groves assigned J. Robert Oppenheimer to organize and oversee the project's Los Alamos Laboratory in New Mexico. Robert Serber named two types of bombs. Led by the Clinton Engineer Works in Oak Ridge, Tennessee, Little Boy was a gun-type fission bomb that used uranium-235. Both weapons used plutonium produced in nuclear reactors at Hanford, Washington, known as Fat Man devices. But the Japanese nuclear weapons program lacked the workforce, minerals and funds of the Manhattan Project, and it never developed an atomic bomb.

Organization and Training

The 509th Composite Group was formed on December 9th and activated on December 17th at Wendover Army Air Field, Utah. Tibbets was tasked with organizing and commanding a combat group to develop atomic weapon delivery systems for Germany and Japan. The group was termed a "composite" rather than a "bombardment" organization because its flying squadrons included bombers and transport aircraft. Due to its isolation, Tibbets chose Wendover over Great Bend, Kansas, and Mountain Home, Idaho. Tibbets deemed his force combat-ready after each bombardier dropped at least 50 inert or conventional pumpkin bombs. Operation Centerboard was codenamed on April 5, 1945. Unfortunately, its allocation officer at the War Department's Operations Division was not cleared to know any facts. Operation Centerboard I was the first bombing, while Centerboard II was the second. The 509th Composite Group has 225 officers and 1,542 enlisted men authorized for deployment to Tinian. The 509th had 51 civilian and military workers from Project Alberta connected to Tinian, the 1st Technical Detachment. 393d Bombardment Squadron, 509th Composite Group, with 15 Silverplate B-29s. These aircraft had fuel-injected engines, Curtiss Electric reversible-pitch propellers, pneumatic actuators for opening and shutting bomb bay doors, and other modifications.

The 509th Composite Group's ground support echelon arrived in Seattle, Washington, on April 26, 1945. On May 6, the SS Cape Victory departed for the Marianas, while the SS Emile Berliner transported group material. Passengers were not allowed to leave the dock area in Honolulu or Eniwetok. Between May 15 and 22, an air echelon advance group of 29 officers and 61 enlisted men flew to North Field on Tinian. Brigadier General Thomas Farrell, deputy commander of the Manhattan Project, and Rear Admiral William R. Purnell of the Military Policy Committee were on hand to make higher policy decisions. They were recognized as the "Tinian Joint Chiefs" with Project Alberta commander Captain William S. Parsons.

Choice of Targets

A map of Japan and the Marianas showing the attacks' paths One goes to Iwo Jima, Hiroshima, and back. The other goes to Kokura, down to Nagasaki, then southwest to Okinawa before returning to Tinian. For Marshall and Stimson to approve, Groves submitted bombing targets in April 1945. From the USAAF, Groves organized a Target Committee, which comprised Farrell and scientists from the Manhattan Project (John von Neumann, Robert R. Wilson, and William Penney). After hearing from Project Alberta's Tibbets and Commander Frederick Ashworth and Manhattan Project's scientific advisor Richard C. Tolman, the Target Committee returned to Washington on May 28th. On the list of potential targets were: Kokura (now Kitakyushu), home to one of Japan's largest weaponries plants; Hiroshima, an embarkation port and industrial centre; Yokohama, a hub for aircraft manufacturing and machine tools; Niigata, a dock with steel and aluminium plants; and Kyoto, a major industrial centre. The target selection criteria were as follows:

• The target was crucial in a large city and had a diameter of over 3 mi (4.8 km).
• The blast would do actual harm.
• By August 1945, it was unlikely to be assaulted.

The Army Air Forces agreed to leave these cities off the target list so an accurate evaluation of the damage inflicted by the atomic bombs could be made. Hiroshima was called "an army depot and embarkation port in the heart of an industrial city. It's a good radar target and big enough to damage a lot of the city. The nearby hills may generate a concentrating effect, increasing the explosion damage. Due to the rivers, it is not a good target." The Target Committee said, "The importance of psychological aspects in target selection was agreed. Kyoto has the advantage of having people who are more highly intelligent and hence more able to grasp the significance of the weapon. Hiroshima's size and likely mountain concentration mean that a huge portion of the city may be destroyed. The Emperor's Palace in Tokyo is the most famous but least strategic target."

Edwin O. Reischauer, a US Army Intelligence Service Japan expert, prevented the Kyoto bombing. However, Reischauer rejected this claim in his autobiography: only Henry L. Stimson, the Secretary of War at the time, who had known and liked Kyoto since his honeymoon there decades earlier, deserves credit for rescuing Kyoto.

After a briefing on May 30, Stimson asked Groves to remove Kyoto from the target list. Groves refused, citing its military and industrial importance. Stimson then approached President Truman. Truman settled with Stimson, and Kyoto was temporarily dropped. In July, Groves tried to reinstate Kyoto, but Stimson refused. Finally, on July 25, Nagasaki replaced Kyoto on the target list. It was a critical military port and a major shipbuilding and repair hub for Japan.

Proposed Demonstration

Stimson formed the Interim Committee in early May 1945, at the request of the Manhattan Project's directors and with Truman's assent. Ernest Lawrence recommended a non-combat demonstration during the May 31 and June 1 sessions. Arthur Compton recalled: Everyone suspected sleight of hand. Without warning, the Japanese air force might still cause havoc if a bomb was dropped on Japan. The atomic bomb was a complex device still under development. Its operation would be unusual. The Japanese defenders may assault during the final adjustments of the bomb. It would be far worse than no attempt at all. We should have only one bomb available first, then others at too-long intervals. We couldn't afford one of them to fail. No way could Japan's dedicated and ardent military men be impressed if the test were conducted on neutral territory. If such an open test could not elicit capitulation, the chance to offer the effective shock of surprise would be lost. It would make the Japanese ready to stop an atomic assault if they could. Although the idea of a non-destructive demonstration was appealing, no one could suggest how it could be made compelling enough to stop the conflict.

The Scientific Advisory Panel rejected physicist James Franck's report on June 16th, saying, "we can offer no technical demonstration likely to terminate the war; we see no acceptable alternative to direct military usage." The Interim Committee convened again on June 21 in Washington, D.C., to re-examine its earlier conclusions. Still, it repeated that using a bomb on a military target was the only option.

The atomic bomb would lose its shock value to demonstrate, and the Japanese could deny it was harmful, making a demonstration less likely to result in surrender. On the other hand, the bomb may murder Allied POWs transferred to the demonstration site. Also, the Trinity test was for a stationary weapon, not an air-dropped bomb. Finally, although more bombs were being manufactured, only two would be accessible by early August, and using one for a demonstration would be costly.

Leaflets

The US had been dropping over 63 million leaflets across Japan for months, warning of possible air raids. Many Japanese cities were destroyed by aerial bombardment. Area-bombing cities were less stigmatized by LeMay's use of leaflets. Despite the warnings, Japanese anti-war protests were futile. Many Japanese chose to flee large cities because they believed the leaflet messages were accurate. Concerned by the leaflets, the authorities demanded their confiscation. Recent Japanese POWs created leaflet writings "to plead to their compatriots".

The Interim Committee's Scientific Panel decided against a demonstration bomb and a special leaflet warning to drop Hiroshima atomic bomb. Those selections were made due to the uncertainty of a successful detonation and the leadership's desire to shock. Hiroshima was not warned that a new, more devastating bomb would be dropped. Various sources disagreed on when the last leaflets were dropped on Hiroshima before the explosion. Robert Jay Lifton wrote 27 July and Theodore H. McNelly 30 July. On July 27, the USAAF attacked eleven cities with leaflets, but Hiroshima was not one of them, and no leaflet sorties occurred on July 30. On August 1 and 4, leafleting was done. Survivor tales mention a delivery of leaflets a few days before the atomic bomb exploded on Hiroshima. A leaflet targeting 11 or 12 locations was produced three times, totalling 33 cities. "we cannot ensure that only these cities will be attacked," reads the brochure in Japanese. It was not listed.

Consultation with Britain and Canada

The Quebec Agreement, reached in 1943, declared that nuclear weapons would not be deployed against another country without mutual permission. Stimson needed British authorization. The Combined Policy Committee met at the Pentagon on July 4, 1945, with one Canadian representative. A decision of the Combined Policy Committee, Field Marshal Sir Henry Maitland Wilson revealed that the British government agreed to use nuclear weapons against Japan. The Quebec Agreement also regulated information distribution to third parties. Therefore the topic shifted to what scientific facts would be provided in the bombing press statement. The group also discussed what Truman could tell Soviet leader Joseph Stalin at the approaching Potsdam Conference, requiring British approval. The interim Chief of Staff, General Thomas T. Handy, signed the attack orders because Marshall was at the Potsdam Conference with Truman. The 509th Composite Team, 20th Air Force will drop its first special bomb on one of the following targets: Hiroshima, Kokura, Niigata, and Nagasaki. Additional aircraft will accompany the bomb-carrying plane to watch and record the aftermath of the bomb's blast. It will be several miles away from the bomb's impact point.

Further bombs will be dropped on the above targets when the project staff is ready. Other targets will be specified in future instructions. Truman noted in his diary that day: Until August 10th, this weapon will be deployed against Japan. I told Mr Stimson, the Secretary of War, to use it to target military objectives, not people and children. Even though the Japanese are barbarians, vicious, brutal, and fanatics, we, as world leaders, cannot drop that horrible bomb on either Kyoto or Tokyo. He and I agree. The target is strictly military.

Potsdam Declaration

The Trinity Test in the New Mexico desert on July 16 exceeded expectations. On July 26, the Allies published the Potsdam Declaration, which defined Japan's surrender terms. If Japan did not surrender, the Allies would attack, resulting in "the inevitable and complete destruction of the Japanese armies, as well as the entire devastation of the Japanese country." The communiqué made no mention of the explosive. According to Japanese media, the Japanese government rejected the proclamation on July 28. At a press conference, Prime Minister Kantar Suzuki said that the Potsdam Declaration was a carbon copy of the Cairo Declaration. His administration would reject it (mokusatsu, "kill by silence"). Japanese and foreign media saw the comments as a rejection of the declaration. No action was taken by Emperor Hirohito, who was waiting for a Soviet response to non-committal Japanese peace requests. There was no occupation of the Japanese Home Islands, Korea, or Formosa, and the punishment of war criminals was delegated to the Japanese government. Truman agreed to Winston Churchill's request that Britain is characterized the minute the atomic bomb was released. Group Captain Leonard Cheshire and William Penney were despatched to Tinian, but LeMay refused them entry. They could only convey a solid message to Wilson.

Bombs

Except for the uranium payload, the Little Boy bomb was ready in early May 1945. A hollow cylindrical bullet and a cylindrical target insert were made of uranium-235. The projectile was finished on June 15 and the target on July 24. From Hunters Point Naval Shipyard in California, the ammunition and eight pre-assembled bombs arrived in Tinian on the cruiser USS Indianapolis on July 26. On July 30, Project Alberta Commander Francis Birch flew with the target insert. Concerned that a B-29 could crash on takeoff, Birch changed the Little Boy design to include a removable breech plug that would allow the bomb to be armed in flight. Project Alberta courier Raemer Schreiber carried the first plutonium core in a magnesium field carrying case developed by Philip Morrison. Not being a neutron reflector, magnesium was chosen. The spirit flew from Kirtland Army Air Field to North Field in a 509th Composite Group C-54 transport aircraft on July 26. F31, F32, and F33 were selected at Kirtland on July 28th by three B-29s, two from the 393d Bombardment Squadron and one from the 216th Army Air Force Base Unit, and transferred to North Field on August 2nd.

Hiroshima During World War II

Nose painted with "Enola Gay" and "82" Seven men face it. A baseball cap is the only one with shorts and a T-shirt. Tibbets is clearly in uniform. Hiroshima was a major industrial and military metropolis at the bombing. The most critical military unit nearby was Field Marshal Shunroku Hata's Second General Army, which controlled the defence of all of southern Japan. Hata's command had some 400,000 men, most of whom were in Kyushu, expecting an Allied invasion. The 59th Army, 5th Division, and 224th Division, a newly established mobile formation, were also in Hiroshima. Anti-aircraft weapons of the 3rd Anti-Aircraft Division, including the 121st and 122nd Anti-Aircraft Regiments and the 22nd and 45th Separate Anti-Aircraft Battalions, defended the city. In addition, 40,000 Japanese soldiers were expected to be stationed in the town.

Hiroshima was a military supply and logistics hub. A central communications hub, shipping harbour, and troop staging region. And it was home to a vast war industry that built parts for planes and boats and guns. The city's core had several reinforced concrete and lighter structures. A dense concentration of small timber workshops in Japanese homes surrounded the centre. Larger industrial plants dotted the city's periphery. Many of the manufacturing structures were also constructed around timber frames. The town was highly flammable. It was Japan's second-largest unaffected city after Kyoto, owing to its absence of an aircraft manufacturing industry, which the XXI Bomber Command targeted. The Joint Chiefs of Staff banned bombers from Kokura, Niigata, and Kyoto on July 3. Before the atomic blast, Hiroshima's population had progressively fallen due to a systematic Japanese government evacuation. The population was 340,000–350,000 at the time of the attack. Residents questioned why Hiroshima had been spared firebombing. Others believed their family in Hawaii and California had petitioned the US authorities to avoid Hiroshima. Realists ordered buildings demolished to construct long, straight firebreaks. These were extended till the morning of August 6, 1945.

The Bombing of Hiroshima

On August 6, Hiroshima was the primary target, with Kokura and Nagasaki as secondary targets. Tibbets' mother's B-29 Enola Gay took off from North Field, Tinian, roughly six hours from Japan. The Great Artiste, instructed by Major Charles Sweeney, carried instruments, and Necessary Evil, commanded by Captain George Marquardt. The photographic plane Necessary Evil. After departing Tinian, the aircraft flew individually to Iwo Jima, where they met Sweeney and Marquardt at 05:55 a.m., at 9,200 feet (2,800 m). At 31,060 feet, the airplane arrived in clean air (9,470 m).  Parsons, the mission's commander, armed the bomb in flight to reduce hazards. He'd seen four B-29s crash and burn on takeoff and thought a B-29 with an armed Little Boy would cause a nuclear catastrophe. Deputy Second Lieutenant Morris R. Jeppson removed the safety devices 30 minutes before the target. During August 5–6, Japanese early warning radar detected numerous American aircraft heading south. Toba, Maebashi, Nishinomiya, Ube and Imabari were all targeted. In many cities, including Hiroshima, radio broadcasting was halted. Hiroshima got the all-clear at 00:05. An hour before the bombing, Straight Flush passed over the city, and the air raid siren went off. It sent out a short message that Enola Gay picked up. : "Low cloud cover at all heights. Primary bombing." At 07:09, Hiroshima received another all-clear. Tibbets began his bomb run at 08:09, handing control over to Major Thomas Ferebee. The drop from an airplane at 31,000 feet (9,400 m) to a detonation height of around 1,900 feet (580 m) over the city took 44.4 seconds. Enola Gay had driven 11.5 mi (18.5 km) before feeling the blast.

The bomb missing the Aioi Bridge by 800 ft (240 m) detonated squarely above Shima Surgical Clinic. A 16 2 kiloton TNT explosion (66.9 8.4 TJ) was released. Only 1.7% of the weapon's material was fissioned. The total devastation radius was 1 mile (1.6 km), resulting in 4.4 square miles of flames (11 km2). The Enola Gay was 10 miles away the minute the bomb exploded and had been for two minutes. They were merely instructed to expect a blinding light and given black goggles, but only Tibbets, Parsons, and Ferebee knew the weapon's nature. "The whole thing was spectacular and awe-inspiring... the soldiers aboard with me gasped 'My God'," Tibbets told reporters. He and Tibbets called the shockwave "ack-ack fire".

Events on the Ground

The detonation and inferno killed 70,000–80,000 people, or 30% of Hiroshima's population at the time, and injured another 70,000. Up to 20,000 Japanese military soldiers were killed. According to US studies, 4.7 square miles (12 km2) of the city was destroyed. Officials estimate that 69 per cent of Hiroshima's structures were destroyed or damaged. Due to the high risk of earthquakes in Japan, several reinforced concrete structures in Hiroshima were built so well that their frames did not collapse even near the explosion centre. Because the bomb detonated in the air, the blast was directed downward rather than sideways, allowing the Prefectural Industrial Promotional Hall, now known as the Genbaku (A-bomb) dome, to survive (the hypocenter). The ruin was designated Hiroshima Peace Memorial and was declared a UNESCO World Heritage Site in 1996, despite US and Chinese protests, citing that other Asian nations suffered the most loss of life and property. A sole focus on Japan lacked historical perspective. The bombing ignited fierce fires engulfed 2 km of timber and paper dwellings (1.2 mi). Unlike in other Japanese cities, the firebreaks failed. After the 07:31 air raid warning, many individuals were outside, going about their business. In the basement of a armored concrete building (after known as the Rest House), approximately 170 meters (560 feet) from ground zero, Eiz Nomura was the closest known survivor. "He died at 84 in 1982."

Akiko Takakura was one of the survivors closest to the hypocenter. She was in the sturdy Bank of Hiroshima, only 300 meters (980 feet) from the attack. This "Hiroshima strike" photo was misinterpreted for decades as the bomb's mushroom cloud at 08:16. A researcher identified the scene in March 2016 as the firestorm cloud that engulfed the city, a firestorm that peaked three hours after the blast. Over 90% of doctors and 93% of nurses were killed or injured in Hiroshima, primarily in the worst-hit downtown district.  The hospitals were wholly devastated. The Red Cross Hospital has only one doctor left, Terufumi Sasaki. The police and volunteers set up evacuation centres at hospitals, schools and tram stations and a morgue in the Asano library by early afternoon.

Mainly on the grounds of Hiroshima Castle, around 900 yards from the hypocenter. Three thousand two hundred forty-three men were killed on the parade ground. The Chugoku Military District Headquarters communications room was placed in a semi-basement in the castle. When the bomb burst, Yoshie Oka, a communications officer from Hijiyama Girls High School, had just sent a message alerting Hiroshima and Yamaguchi. She used a particular phone to notify Fukuyama HQ (some 100 km away), "A new bomb has hit Hiroshima. The city is nearly destroyed." Field Marshal Shunroku Hata took over the city's government, lightly injured while eating breakfast with his son and granddaughter. Many of his staff were killed or wounded, including a Korean Prince, Yi U, a lieutenant colonel in the Japanese Army. Hata's chief of staff was the injured Colonel Kumao Imoto. Soldiers from Hiroshima Ujina Harbor utilized Shiny-class suicide motorboats to gather the wounded and transport them to the military hospital at Ujina. Trains and trucks hauled in supplies and evacuated survivors. American airmen were held in the Chugoku Military Police Headquarters, around 1,300 feet (400 m) from the hypocenter. Two detainees critically injured by the bombing were left by the Kempei Tai close to the Aioi Bridge, stoned to death. The Japanese authorities reported their deaths as atomic blasts to cover up the ends of eight US POWs at Kyushu University.

Japanese Realization of the Bombing

The Japan Broadcasting Corporation's Tokyo control operator observed the Hiroshima station had gone dark. He tried again using another phone line, but it also failed. The Tokyo railroad telegraph headquarters discovered the main line telegraph had failed just north of Hiroshima. Unofficial and confused reports of a massive explosion in Hiroshima emerged from local railway stops within 16 km (10 mi). These reports were sent to the Imperial Japanese Army General Staff headquarters. Military bases kept calling Hiroshima's Army Control Station. The General Staff was astonished by the city's total stillness; they knew no significant enemy raid had happened, and no large explosives stockpile was present. Finally, a young officer was sent to Hiroshima to inspect the damage and report to Tokyo with reliable information. The rumour of an explosion was dismissed as unfounded. The staff officer flew to the southwest. After a three-hour flight, he and his pilot spotted a massive cloud of smoke from the bomb's firestorm. After surveying the devastation, they landed south of the city, where the staff officer began organizing relief operations after reporting to Tokyo. President Truman's declaration of the strike sixteen hours later was Tokyo's first hint of the new bomb's destruction.

Truman announced the employment of the new weapon after the Hiroshima attack. That the German atomic bomb research failed, and that the US and its allies had "invested two billion dollars on the biggest scientific bet in history—and won," he said. Truman then forewarned, "If they do not accept our demands immediately, they can expect a catastrophic deluge from the sky. Following this air attack will be sea and land forces in unprecedented numbers and fighting skill." It was a widely reported speech in Japan.

509th Composite Group dropped leaflet AB12 over Japan on August 9th, with information about the Hiroshima bomb and a warning to petition the Emperor for surrender. Saipan's 50,000-watt OWI radio station aired a similar message to Japan every 15 minutes, affirming that extra Japanese cities would face a similar fate unless the Potsdam Declaration were immediately accepted and urging residents to evacuate critical towns. Radio Japan, which never surrendered, alerted the Japanese of Hiroshima's single-bomb annihilation. Prime Minister Suzuki reaffirmed his government's commitment to disregard Allied demands and fight on the Japanese press. On April 5, Soviet Foreign Minister Vyacheslav Molotov informed Tokyo of the unilateral Soviet–Japanese Neutrality Pact abrogation.

 On August 9, at 2 a.m. Tokyo time, Soviet troops, armour, and air forces launched the Manchurian Strategic Offensive. Tokyo learned of the Soviet Union's formal war declaration four hours later. With the approval of Minister of War Korechika Anami, the Japanese Army began preparing to implement martial law across the country to halt any attempts at peace. Dr Yoshio Nishina and other atomic scientists arrived in Hiroshima on August 7, one day after the bombing. They returned to Tokyo and informed the cabinet that Hiroshima had been destroyed. "There would be more destruction, but the fight would carry on," said Admiral Soemu Toyoda, Chief of the Naval General Staff. American Magic decoded the cabinet's messages. A group of six leaders met in Guam the same day to plan the next steps. They decided to drop another bomb because Japan was not showing signs of surrendering. Parsons claimed Project Alberta would have it ready by August 11, but Tibbets indicated a storm that day would make flying difficult, so he asked if the bomb could be ready by August 9. Parsons said he'd try.

Nagasaki Throughout World War II

Nagasaki was one of southern Japan's busiest seaports during WWII, producing artillery, ships, military equipment, and other war materials. Mitsubishi Shipyards, Arms Plant, Electrical Shipyards, and Steel and Arms Works accounted for roughly 90% of the city's labour force and industry. Nagasaki, a major industrial city, was spared firebombing due to its challenging nighttime location with AN/APQ-13 radar.

Unlike the other target cities, Nagasaki was not exempt from the Joint Chiefs of Staff's July 3 command. On August 1, several conventional high-explosive bombs were dropped on the town. Some hit the southwest city shipyards and docks, and others hit the Mitsubishi Steel and Arms Works. In addition, a 7 cm (2.8 in) anti-aircraft gun battery and two searchlight batteries were deployed to defend the city by early August.

Unlike Hiroshima, practically all structures were traditional Japanese, with wood walls (plastered or not) and tile roofs. Many smaller businesses and enterprises were also located in arrangements made of wood or other non-explosion resistant materials. For many years, Nagasaki had been allowed to flourish without a defined city zoning plan; homes were built next to factories and near each other throughout the industrial valley. On the day of the bombing, 240,000 Japanese, 10,000 Koreans, 2,500 recruited Korean workforces, 9,000 Japanese soldiers, 600 conscripted Chinese workers, and 400 Allied POWs were in Nagasaki.

The Bombing of Nagasaki

Tibbets was in charge of the timing of the second attack. The raid against Kokura was moved up two days to avoid five days of poor weather anticipated to start on August 10. Three bomb pre-assemblies labelled F-31, F-32, and F-33 were transported to Tinian. Swaney performed a dress rehearsal off Tinian on August 8 with Bockscar as the drop plane. For the 9 August mission, F-31 was designated for assembly F-33. A Bockscar piloted by Sweeney's crew took off from Tinian island carrying Fat Man at 03:47 Tinian time, 02:47 Japanese time on the morning of August 9th, 1945. Two B-29s flew an hour ahead as weather scouts for the second attack, while two more B-29s flew with Sweeney for instruments and photographic support. He left with his weapon, but the electrical safety plugs were still engaged.

The flight engineer informed Sweeney that an inoperative fuel transfer pump prevented the use of 640 US gallons of reserve fuel., this fuel would still need to be transported to Japan and back by using more power. Replacing the pump would take hours, and transporting the Fat Man, a live explosive, would be risky. Tibbets and Sweeney chose Bockscar to complete the mission. Penney and Cheshire were allowed to fly as observers on the group's third plane, Big Stink, piloted by Major James I. Hopkins, Jr. Weather planes reported both targets clear. Unfortunately, big Stink missed the rendezvous point for Sweeney's flight off the coast of Japan. As agreed with Sweeney and Captain Frederick C. Bock, Hopkins was flying tight circles over Yakushima as agreed with Cheshire and Captain Frederick C. Bock, piloting the support B-29 The Great Artiste. Hopkins instead passed 40-mile (64 km) doglegs. Sweeney waited for Big Stink for 40 minutes after being told to stop after 15 minutes. Sweeney checked with Ashworth, the bomb's supervisor, before leaving. Sweeney, the plane's commander, chose the main, Kokura.

Bockscar, escorted by The Great Artiste, drove thirty minutes to Kokura. The previous day's massive firebombing raid by 224 B-29s on nearby Yahata had resulted in clouds and drifting smoke over Kokura. The Yahata Steel Works also deliberately burnt coal tar to produce black smoke. The clouds and smoke obscured 70% of the aiming point over Kokura. It took 50 minutes for three bomb runs, exposing the aircraft to heavy defences near Kokura, but the bombardier could not drop visually. Second Lieutenant Jacob Beser, monitoring Japanese communications, reported activity on the Japanese fighter direction radio bands by the third bomb run. Because the gasoline pump had failed, Bockscar and The Great Artiste headed for Nagasaki.

Bockscar had inadequate fuel to reach Iwo Jima and would be forced to reroute to Okinawa, which had only six weeks previously become Allied-occupied territory. Ashworth agreed with Sweeney's notion that if Nagasaki were veiled, the crew would move the bomb to Okinawa and place of it in the seas if required. Nagasaki received an air raid warning at 07:50, but the all-clear came at 08:30. No further action was taken when only two B-29 Superfortresses were seen at 10:53 JST (GMT+9).

The Great Artiste then parachuted instruments attached to three parachutes at 11:00 a.m. One of the instruments also had an anonymous note sent to Professor Ryokichi Sagane, a physicist ans scientist at the University of Tokyo who studied with three scientists responsible for the atomic bomb at the University of California, Berkeley. It took a month for the military to find the messages and hand them over to Sagane Luis Alvarez, one of the authors, met Sagane in 1949 and signed the letter. Captain Kermit Beahan, Bockscar's bombardier, visually sight the target at 11:01 a.m. The Fat Man weapon dropped over the city's industrial valley had around 5 kg (11 lb) of plutonium. It blew up around 11:02 a.m. at 1,650 33 ft (503 10 m), halfway amid the Mitsubishi Steel and Arms Works and the Nagasaki Arsenal. The blast was contained to the Urakami Valley, and the intervening hills shielded much of the city. The resulting explosion emitted 21 2 kt (87.9 8.4 TJ). Big Stink, who was 100 miles away, flew over to investigate.

Bockscar continued to Okinawa, arriving with only one approach. Sweeney repeatedly tried to call the control tower but got no response. He could see several planes landing and flying off from Yontan. The Bockscar came in reckless, landing at 140 miles per hour instead of the typical 120 miles per hour. As he approached the final approach, the number two engine died. Bockscar bounced up into the air for roughly 25 feet (7.6 m) before smashing back down forcefully. Before the pilots regained control, the B-29 slewed left towards a row of parked B-24 bombers. With both pilots on the brakes, Bockscar made a swerving 90-degree turn at the end of the runway to avoid running off it. The plane stopped after the second engine ran out of fuel.

Following the mission, the plane's identification was unclear. According to combat journalist William L. Laurence of The New York Times, who joined the operation onboard Bock's aircraft, Sweeney led the mission in The Great Artiste. He noted its "Victor" number as 77, Bockscar's. Laurence knew Sweeney and his crew called their plane The Great Artiste. But, as Laurence noticed in his story, only Enola Gay's B-29s had names painted on the noses. As a result, Laurence mistook Victor 77 for The Great Artiste when Victor 89.

Events on the Ground

The bomb was more powerful than Hiroshima's, but hillsides limited its effects to the Urakami Valley. Of the 7,500 Japanese personnel at the Mitsubishi Munitions plant, 6,200 were murdered. 17,000–22,000 more killed at other war plants and companies in the city. Estimates of immediate deaths range from 22,000 to 75,000 people. In addition, 35,000–40,000 people died, and 60,000 were injured. After the blast, several persons perished from their injuries. Because of unauthorized foreign workers and military personnel in transit, estimates of total deaths by the end of 1945 varied from 39,000 to 80,000. Unlike Hiroshima, just 150 Japanese soldiers died instantly, including 36 from the 4th AAA Division's 134th AAA Regiment. The bombing killed at least eight and maybe thirteen Allied POWs. A British POW, Ronald Shaw, and seven Dutch POWs were among the eight confirmed deaths. Joe Kieyoomia, an American POW in Nagasaki at the time of the attack, survived thanks to the concrete walls of his cell. All 24 Australian POWs in Nagasaki survived. Nagasaki child partly incinerated Ysuke Yamahata's photo taken a day after the explosion and building fires. Once the Americans seized control of Japan, they censored all images, even those from the conventional bombing of Tokyo, preventing Yamahata's photographs from being distributed. The ban was abolished in 1952. Fires spread across the northern portion of the city to 2 mi (3.2 km) south of the bomb's radius of utter destruction.

The Mitsubishi Arms Plant and the Mitsubishi Steel Works were also devastated. In the primary disaster zone, just 10% of the Mitsubishi Electric Works was damaged. The blast shattered the Nagasaki Arsenal. Unlike Hiroshima, where a firestorm occurred due to the fuel density, Nagasaki's destroyed areas did not provide enough fuel for the phenomena. Instead, the wind propelled the fire down the valley.

The blast disrupted the city's medical facilities. The Shinkozen Primary School became the major medical centre and a temporary hospital. The trains were still running, bringing several victims to local hospitals. Finally, a nighttime medical team from a military hospital arrived, and nearby towns' fire departments helped fight the blazes. Takashi Nagai was a radiologist at Nagasaki Medical College Hospital. His right temporal artery was cut, yet he joined the rest of the surviving medical personnel in treating bomb casualties.

But a second Little Boy bomb (using U-235) wouldn't be available until December 1945; Groves predicted another "Fat Man" bomb on August 19, three more in September, and three more in October. Then, on August 10, he wrote to Marshall that "the next bomb should be ready for delivery on the first appropriate weather following August 17 or 18." "It is not to be excreted on Japan shorn of formal approval from the President," Marshall wrote, echoing Truman's request that day. As a result, the earlier order to attack the target cities with atomic bombs "as made ready" was changed. Instead, Marshall suggested that the remaining cities on the target list be spared atomic bomb attacks to Stimson.

LeMay instructed Tibbets to return to Albuquerque, New Mexico, to gather two more Fat Man assemblies. At Los Alamos, technicians cast another plutonium core for 24 hours. Next, it needed to be pressed and coated, which took until August 16. Finally, it may have been used on August 19. To reach Marshall, Groves ordered the core not shipped on August 13.

Day after the Nagasaki explosion, Ysuke Yamahata arrived in the city with a reporter and an artist to record the destruction for maximum propaganda. Yamahata captured hundreds of photos published in the Mainichi Shimbun on August 21. The firsthand narrative by Leslie Nakashima appeared in American publications. The New York Times reprinted his UPI report on August 31. Wilfred Burchett arrived alone by rail from Tokyo to Hiroshima on September 2, 1945. The Daily Express in London published his Morse code transmission "The Atomic Plague" on September 5, 1945. The Nakashima and Burchett papers were the first public reports to mention radiation burns and radiation poisoning. The US military disapproved of Burchett's reporting, accusing him of being influenced by Japanese propaganda. William Laurence ignored the allegations of radiation sickness, ignoring his account published a week earlier.

Lieutenant Daniel McGovern of the US Strategic Bombing Survey used a camera to record the effects of the bombings in early 1946. After shooting 90,000 feet (27,000 meters) of film, The Effects of the Atomic Bombs Against Hiroshima & Nagasaki was created. The documentary displayed burned-out buildings and cars and rows of heads and bones on the ground. It remained "secret" for 22 years. In September 1945, Nippon Eigasha sent cameramen to Nagasaki and Hiroshima. Then, in a Nippon Eigasha cameraman to cease shooting in Nagasaki on October 24, 1945. The Americans seized Nippon Eigasha's reels, but the Japanese government had them declassified. Though some research on the impact of the strike was banned under Japan's occupation, the Hiroshima-based magazine Chugoku Bunka's inaugural edition on March 10, 1946, detailed the damage from the explosion. By Pulitzer Prize winner John Hersey, Hiroshima reached Tokyo in English by January 1947, and the translated version reached Japan in 1949.

It chronicled the lives of six bomb survivors in the weeks and months before and after the Little Boy bombing. The Unforgettable Fire was a book and exhibition of drawings and artwork created by survivors of the bombings in 1974. Otto Hahn and other German atomic physicists were stunned by the bombing. When Hahn announced that an atomic weapon "might be achievable in another twenty years," Werner Heisenberg was sceptical. Weizsäcker said, "I think it's terrible of the Americans. But Heisenberg countered, "One could equally well say 'That's the quickest way to end the war'. "We would have demolished London but still not conquered the globe," Karl Wirtz remarked, "and then they would have dropped them on us."

The Vatican concurred, expressing regret that the bomb's creators did not destroy the weapon for humanity. The Dean of St Albans, Rev. Cuthbert Thicknesse, disallowed a thanksgiving service at St Alban's Abbey, calling atomic weapons "an act of vast, indiscriminate killing." Nonetheless, the news of the nuclear attack was enthusiastically received in America, with a sizable minority of Americans (23%) calling for additional atomic bombs to be launched on Japan. The public's first positive response was backed up by imagery (mainly the powerful images of the mushroom cloud).  In America, it was regular practice to exclude graphic pictures of death from films, publications, and newspapers.

In 1945, an estimated 90,000-140,000 people perished in Hiroshima (up to 39%) and 60,000-80,000 in Nagasaki (up to 32%), while the number died directly from the blast, heat, or radiation is uncertain. Six thousand eight hundred eighty-two persons were evaluated in Hiroshima and 662 in Nagasaki, primarily within 2,000 meters of the hypocenter, who sustained injuries from the blast and heat but died from complications frequently aggravated by acute radiation sickness (ARS), all within 20 to 30 days. The most famous was Midori Naka, who lived 650 meters from the hypocenter in Hiroshima and died on August 24, 1945. The first death was officially recognized as a result of radiation illness, or "atomic bomb disease", which was called radiation illness by many. Smaller doses were made fatal when the subject had a concurrent blast or burned polytraumatic injuries, which was not realized at the time. The risk of sepsis and death increases when a non-lethal radiation dosage moderately reduces the white blood cell count.

The Atomic Bomb Casualty Commission was formed in spring 1948 following Truman's presidential direction to the National Academy of Sciences–National Research Council to investigate the late effects of radiation on Hiroshima and Nagasaki survivors. From Hiroshima and Nagasaki: The Effect of Atomic Bomb Exposure on Pregnancy Termination, 1956. On April 1, 1975, the ABCC became the RERF. The RERF is still today, run by the US and Japan.

Cancer Increases

Radiation-induced cancer has a minimum latency period of five years, and leukaemia has a minimum of two years, peaking six to eight years later. For the first time, Dr Jarrett Foley published a significant study on the latter's rising occurrence among After 1950, almost all instances of leukaemia were in those exposed to more than 1Gy. The Radiation Effects Research Foundation's 1987 Life Span Study found a statistical excess of 507 tumours of unknown lethality in 79,972 hibakusha who lived between 1958 and 1987. The RERF believes that from 1950 to 2000, 46% of leukaemia fatalities, including Sadako Sasaki, and 11% of solid cancer deaths were likely due to radiation from the bombs or other post-attack city impacts, with a statistical excess of 200 leukaemia deaths and 1,700 notable cancer deaths. Both statistics come from the examination of around half of the total survivors. A 2016 meta-analysis indicated that while radiation exposure increases cancer risk, it only reduces survivors' average lifetime by a few months.

Congenital Disability Investigations

Intrauterine radiation exposure of "at least 0.2 Gy" during the preimplantation phase can induce implantation problems and death of the human embryo. During this radiosensitive era, the number of miscarriages caused by the bombings is unknown. The ABCC studied the results of pregnancies in Hiroshima, Nagasaki, and Kure, a city 18 mi (29 km) south of Hiroshima, to determine the conditions and outcomes connected to radiation exposure. The study's lead author, James V. Neel, showed no substantial increase in birth abnormalities among offspring of survivors who were expecting at the time of the bombings. He also researched the survivors of Hiroshima and Nagasaki, finding that between 90 and 95 per cent were still alive 50 years later. A statistically negligible rise in birth abnormalities occurred directly after the bombings of Nagasaki and Hiroshima when the cities were taken as wholes, based on distance from the hypocenters. The incidence of microencephaly and anencephaly was over three times expected compared to a control group in Kure, where approximately 20 cases were observed in a similar sample.

In 1985, geneticist James F. Crow of Johns Hopkins University verified Neel's findings that birth abnormalities were not higher in Hiroshima and Nagasaki. Many ABCC and RERF members were still investigating suspected congenital disabilities among survivors decades later but found no indication that they were frequent or inherited in survivors' offspring.

Investigations into Brain Development

Despite the small sample size of about 1,600-1,800 people who were prenatally exposed at the time of the bombings and who were both close to the two hypocenters, data from this cohort do support the increased risk of severe mental retardation (SMR), which was observed in about 30 people. While the small sample size of only 30 people out of 1800 makes it difficult to determine a threshold dose, the data collected suggests a threshold intrauterine or the fetal amount of approximately "0.09" to "0.15" Gy for SMR, at the most radiosensitive period of cognitive development, when there are the most undifferentiated neural cells (8 to 15 weeks post-conception), with the risk then linearly increasing to a.

But none of the prenatally exposed to the bombings at an age less than eight weeks, that is before synaptogenesis, or at a gestational age more than 26 weeks "were observed to be mentally retarded", with the condition being limited to those aged 8–26 weeks and absorbing between "0.09" and "0.15" Gy of prompt radiation energy.

Prenatal exposure to greater than 0.1 to 0.5 grey during the same gestational period of 8–25 weeks resulted in a statistically significant decline in both IQ and school records. "There is no indication of a radiation-related influence on scholastic achievement" outside of this time frame.

In both SMR and cognitive performance data, dosages are typically reported in absorbed energy in greys and rads rather than the biologically meaningful, biologically weighted Sievert. It is suggested that the reported threshold dose variance between the two cities is a manifestation of the variance amid X-ray and neutron absorption, with Little Boy emitting significantly more neutron flux. In contrast, the Baratol that enclosed the core of Fat Man filtered or lifted the engross neutron-radiation outline so that the dose of radiation energy received in Nagasaki is primarily that from contact to x-rays/gamma rays, in contrast to the environment within. Because the Little Boy bomb design was never tested before or after deployment, the estimated radiation profile absorbed by individuals at Hiroshima required more reliance on calculations than the Japanese soil, concrete, and roof-tile measurements, which began to reach Accu, With "no statistically significant linear relationship seen" in many other studies into cognitive outcomes such as schizophrenia from prenatal exposure, there is some evidence that in the most severely exposed, those who survived within a few kilometres of the hypocenters, a trend similar to SMR may emerge. However, the sample size may be too small to determine any significance.

The survivors of the bombings are termed Hibakusha, which means explosion-affected people in Japanese. Japan has acknowledged about 650,000 hibakushas. One hundred twenty-seven thousand seven hundred fifty-five survived as of March 31, 2021, mainly in Japan. The Japanese government recognises roughly 1% of these as having radiation-related ailments. The names of Hibakusha who perished after the bombings are listed on the memorials at Hiroshima and Nagasaki. The memorials record the names of about 520,000 hibakushas, 328,929 in Hiroshima and 189,163 in Nagasaki, as of August 2021. Due to public unawareness about the significances of radiation sickness or the low amounts that the mainstream received were fewer than a routine diagnostic x-ray, much of the public still believes that the Hibakusha transmit some genetic or even contagious disease even though there was no statistically significant increase in congenital disabilities/congenital deformities among children born to survivors of Hiroshima and Nagasaki. Among children born to cancer survivors who had previously received radiotherapy. The survivors of Hiroshima and Nagasaki who could conceive had children with no higher incidence of abnormalities/birth problems than the Japanese average. However, survivors of the bombs had more excellent rates of anxiety and somatization symptoms 17–20 years later, according to a study on long-term psychological impacts.

Double Survivors

Around 200 Hiroshima residents sought safety in Nagasaki. Sixty-five nij hibakusha (lit. twofold explosion-affected people) were documented in the 2006 documentary Twice Survived: The Doubly Atomic Bomb of Hiroshima and Nagasaki. Tsutomu Yamaguchi was officially acknowledged as a double hibakusha on March 24, 2009. He was on a business trip in Hiroshima, 3 km from ground zero when the bomb went off. They spent the night in Hiroshima due to severe left-side burns. He arrived in Nagasaki the day before the attack and was exposed to radiation while looking for his relatives. He was the first confirmed survivor of both attacks. He died of stomach cancer on January 4, 2010, at 93.

Korean Survivors

Japan forcefully laboured up to 670,000 Koreans during the war. 5,000–8,000 Koreans died at Hiroshima, 1,500–2,000 in Nagasaki. For many years, Korean survivors battled for the same recognition as Hibakusha as all Japanese survivors, resulting in a denial of free health benefits in Japan. Most issues were resolved in 2008 via lawsuits.

Hiroshima

Typhoon Ida hit Hiroshima on September 17, 1945. More than half of the city's bridges were destroyed, and highways and railroads were devastated, from 83,000 shortly after the bombing to 146,000 in February 1946. Thanks to the 1949 Hiroshima Peace Memorial City Construction Law, the city was rebuilt. It contributed land previously owned by the national government and utilized for military reasons and money for reconstruction. The Hiroshima Peace Memorial Park design was chosen in 1949. The Hiroshima Peace Memorial was established in the Hiroshima Prefectural Industrial Promotion Hall, the bomb's nearest survivor. The Hiroshima Peace Memorial Museum unlocked in 1955. Nipponzan-Myhji built a Peace Pagoda near Hiroshima in 1966.

Nagasaki

Nagasaki was also reconstructed after the war, although differently. First, reconstruction was sluggish, with simple emergency housing not given until 1946. The focus of rebuilding was on foreign trade, shipbuilding, and fishing. In May 1949, the Nagasaki International Culture City Reconstruction Law announced this. Due to a growth in Christianity, new temples and churches were built. An arch and torii at Sann Shrine at ground zero were constructed from the rubble. The Nagasaki Atomic Bomb Museum opened in the mid-1990s.

Scholars and the public have debated the bombings' involvement in Japan's surrender and the ethical, legal, and military difficulties surrounding the US' rationale. On the one hand, the bombings allegedly caused the Japanese to surrender, avoiding an invasion. Stimson mentioned saving a million lives. The naval blockade could have starved the Japanese into submission without a charge, but many more Japanese would have died. On the other hand, some critics claim that atomic weapons are intrinsically unethical and that the bombings were war crimes and state terrorism.

According to Japanese historian Tsuyoshi Hasegawa, the Soviet Union's involvement in the war "had a considerably greater impact than the atomic bombs" in forcing Japan to surrender. The theory of atomic diplomacy, popularized by American historian Gar Alperovitz in 1965, is that the US utilized nuclear weapons to threaten the USSR in the early phases of the Cold War. James Orr wrote that this theory gained acceptance in Japan and may have influenced US policy.

The way World War II ended influenced international relations for decades. By June 30, 1946, the US had nine atomic bombs in its arsenal, all Fat Man devices like the one used in Nagasaki. The nuclear weapons were handcrafted, and much work remained to enhance their ease of assembly, safety, reliability, and storage. The wartime development pressures prevented many of their performance's suggested or recommended enhancements. However, in October 1947, he reported a military necessity for 400 atomic bombs. So on monopolized nuclear weapons for four years before the USSR tested one in September 1949. The US replied by developing the hydrogen bomb, a thousand-fold more potent than the Hiroshima and Nagasaki bombs. Ordinary fission bombs would now be considered tactical nuclear weapons. By 1986, the US possessed 23,317 nukes, while the USSR had 40,159. Russia and the US included about 90% of the world's 13,865 nuclear weapons in early 2019. By 2020, nine countries had nuclear weapons, but not Japan.

Japan reluctantly joined the NPT in February 1970 but remained under the American nuclear umbrella. American nuclear weapons were held in Okinawa and sometimes in Japan, violating bilateral agreements. Due to a lack of resources, the Western Alliance relied on nuclear weapons to defend itself during the Cold War, a posture known as the New Look in the 1950s. After Hiroshima and Nagasaki, the US would repeatedly threaten to deploy nuclear bombs.

On July 7, 2017, over 120 countries voted to adopt the UN Nuclear Weapons Treaty. "The world has been waiting for this lawful standard for 70 years," said Elayne Whyte Gómez, President of the UN discussions on the nuclear ban treaty. But, unfortunately, Japan hasn't signed by 2020.