The U.S. then constructed airfields on Saipan and Tinian where B-29s were based to conduct strategic bombing missions against the Japanese mainland until the end of World War II , including the nuclear attacks on Hiroshima and Nagasaki .

They were the first nuclear weapon tests Testing since Trinity in July 1945 , and the first detonations of nuclear devices since the atomic bombing Attack of Nagasaki on August 9 , 1945 .

A fleet of 95 target ships was assembled Come_together in Bikini Lagoon and hit Attack with two detonations of Fat Man plutonium implosion-type nuclear weapons of the kind dropped on Nagasaki , each with a yield of .

The planned Arranging operation Military_operation was canceled Change_event_time when Japan surrendered Surrendering following the atomic bombings Attack of Hiroshima and Nagasaki , the Soviet declaration of war Hostile_encounter and the invasion Attack of Manchuria .

Another B-29 dropped Motion_directional a plutonium implosion bomb ( `` Fat Man '' ) on Nagasaki three days later .

Japan surrendered Surrendering to the Allies on August 15 , six days after the Soviet Union 's declaration Expressing_publicly of war and the bombing Attack of Nagasaki .

The war culminated Process_end in the atomic bombings of Hiroshima and Nagasaki , and other large aerial bomb attacks Attack by the Allies , accompanied GetReady by the Soviet Union 's declaration Expressing_publicly of war and invasion Attack of Manchuria and other territories on 9 August 1945 , resulting in Causation the Japanese announcement Expressing_publicly of intent to surrender Surrendering on 15 August 1945 .

During early August 1945 , the cities of Hiroshima and Nagasaki were struck Attack and mostly destroyed Destroying by atomic bombs .

Despite continuing to occupy part of China 's territory , Japan eventually surrendered Surrendering on September 2 , 1945 , to Allied forces following the atomic bombings Attack of Hiroshima and Nagasaki and the Soviet invasion Attack of Japanese-held Manchuria .