The Attacks in August 1945
For several months, the U.S. had dropped more than 63 million leaflets across Japan warning civilians of air raids. Leaflet texts were prepared by recent Japanese prisoners of war because they were thought to be the best choice “to appeal to their compatriots.” It is very likely that Hiroshima was leafleted in late July or early August, as survivor accounts talk about a delivery of leaflets a few days before the atomic bomb was dropped. The warnings were not effective. The Japanese regarded the leaflet messages as truthful, but anyone who was caught in possession of one was arrested.
On July 26, 1945, 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.” On July 28, Japanese papers reported that the declaration had been rejected by the Japanese government. Emperor Hirohito, who was waiting for a Soviet reply to a request for help, made no move to change the government position.
Hiroshima was the primary target of the first nuclear bombing mission on August 6, with Kokura and Nagasaki as alternative targets. Having been fully briefed, the 393d Bombardment Squadron B-29 Enola Gay, piloted by Paul Tibbets, took off from North Field, Tinian, about six hours’ flight time from Japan. The Enola Gay (named after Tibbets’ mother) was preceded by two B-29 weather scouts and accompanied by two other B-29s, one to carry instrumentation and one to take photographs.
At 08:09 Tibbets started his bomb run and handed control over to his bombardier. Instead of prior to departure, the bomb was armed, but activated in flight to minimize the risks during takeoff. The release at 08:15 (Hiroshima time) went as planned, and Little Boy took 44.4 seconds to fall from the aircraft flying at about 31,000 feet (9,400 m) to a detonation height of about 1,900 feet (580 m) above the city. Enola Gay traveled 11.5 mi (18.5 km) before it felt the shock waves from the blast.
After the Hiroshima bombing, Truman issued a statement announcing the use of the new weapon. Truman then warned Japan: “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.”
The Japanese government did not react.
On August 5 the Soviet Foreign Minister informed Tokyo of the Soviet Union’s unilateral abrogation of the Soviet–Japanese Neutrality Pact.
On August 7, a day after Hiroshima was destroyed, the Chief of the Naval General Staff and the cabinet estimated that no more than one or two additional bombs could be readied, so they decided to endure the remaining attacks, acknowledging “there would be more destruction but the war would go on”. American Magic Codebreakers intercepted the cabinet’s messages.
At two minutes past midnight on August 9, Tokyo time, Soviet infantry, armor, and air forces launched the Manchurian Strategic Offensive Operation. Four hours later, word reached Tokyo of the Soviet Union’s official declaration of war.
Since there was no indication of Japan surrendering, President Truman and his advisers decided to proceed with dropping another bomb, which could be ready by August 11. When Tibbets pointed to weather reports indicating poor flying conditions on that day due to a storm, the date was changed to August 9.
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 S. Truman, August 9, 1945
At 03:49 on the morning of August 9, 1945, Bockscar, flown by Sweeney’s crew, carried 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.
After three runs over the city, and with fuel running low because of a failed fuel pump, they headed for their secondary target, Nagasaki. At 11:01, a last-minute break in the clouds over Nagasaki allowed Bockscar’s bombardier to visually sight the target as ordered. The Fat Man weapon was dropped over the city’s industrial valley and exploded 47 seconds later at 1,650 ± 33 ft (503 ± 10 m), above a tennis court, slightly off the target.
On August 9 Hirohito ordered his closest advisor 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 Shigenori Tōgō to notify the Allies that Japan would accept their terms on one condition, that the declaration “does not comprise any demand which prejudices the prerogatives of His Majesty as a Sovereign ruler.”
On August 12, the Emperor informed the imperial family of his decision to surrender. 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 (see my previous BlogPost).
In his declaration, without mentioning the Soviets’ attack as the main factor for surrender, 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. This is the reason why We have ordered the acceptance of the provisions of the Joint Declaration of the Powers.”
Days of Victory
“Today the guns are silent. A great tragedy has ended. A great victory has been won. The skies no longer rain death — the seas bear only commerce — men everywhere walk upright in the sunlight. The entire world is quietly at peace. The holy mission has been completed… And so, my fellow countrymen, today I report to you that your sons and daughters have served you well and faithfully.”
— General Douglas MacArthur in a broadcast following the surrender of Japan on August 15, 1945
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Ronny Herman de Jong