<P> Via Ultra intercepts, the Allies also detected increased diplomatic and military traffic, which was taken as evidence that the Japanese were preparing an "all - out banzai attack ." President Truman ordered a resumption of attacks against Japan at maximum intensity "so as to impress Japanese officials that we mean business and are serious in getting them to accept our peace proposals without delay ." The United States Third Fleet began shelling the Japanese coast . In the largest bombing raid of the Pacific War, more than 400 B - 29s attacked Japan during daylight on August 14, and more than 300 that night . A total of 1,014 aircraft were used with no losses . </P> <P> In the longest bombing mission of the war, B - 29s from the 315 Bombardment Wing flew 6,100 km (3,800 mi) to destroy the Nippon Oil Company refinery at Tsuchizaki on the northern tip of Honshū . This was the last operational refinery in the Japan Home Islands, and it produced 67% of their oil . After the war, the bombing raids were justified as already in progress when word of the Japanese surrender was received, but this is only partially true . </P> <P> At the suggestion of American psychological operations experts, B - 29s spent August 13 dropping leaflets over Japan, describing the Japanese offer of surrender and the Allied response . The leaflets had a profound effect on the Japanese decision - making process . As August 14 dawned, Suzuki, Kido, and the Emperor realized the day would end with either an acceptance of the American terms or a military coup . </P> <P> The Emperor met with the most senior Army and Navy officers . While several spoke in favor of fighting on, Field Marshal Shunroku Hata did not . As commander of the Second General Army, the headquarters of which had been in Hiroshima, Hata commanded all the troops defending southern Japan--the troops preparing to fight the "decisive battle". Hata said he had no confidence in defeating the invasion and did not dispute the Emperor's decision . The Emperor asked his military leaders to cooperate with him in ending the war . </P>

When did germany and japan surrender in wwii