Hard-fought battles on the Japanese islands of Iwo Jima , Okinawa , and others resulted in horrific casualties on both sides but finally produced a Japanese defeat . Of the 117,000 Okinawan and Japanese troops defending Okinawa , 94 percent died . Faced with the loss of most of their experienced pilots , the Japanese increased their use of kamikaze tactics in an attempt to create unacceptably high casualties for the Allies . The US Navy proposed to force a Japanese surrender through a total naval blockade and air raids . Many military historians believe that the Okinawa campaign led directly to the atomic bombings of Hiroshima and Nagasaki , as a means of avoiding the planned ground invasion of the Japanese mainland . This view is explained by Victor Davis Hanson : " because the Japanese on Okinawa ... were so fierce in their defense ( even when cut off , and without supplies ) , and because casualties were so appalling , many American strategists looked for an alternative means to subdue mainland Japan , other than a direct invasion . This means presented itself , with the advent of atomic bombs , which worked admirably in convincing the Japanese to sue for peace unconditionally , without American casualties . " Towards the end of the war as the role of strategic bombing became more important , a new command for the United States Strategic Air Forces in the Pacific was created to oversee all US strategic bombing in the hemisphere , under United States Army Air Forces General Curtis LeMay . Japanese industrial production plunged as nearly half of the built-up areas of 67 cities were destroyed by B-29 firebombing raids . On 9 – 10 March 1945 alone , about 100,000 people were killed in a conflagration caused by an incendiary attack on Tokyo . LeMay also oversaw Operation Starvation , in which the inland waterways of Japan were extensively mined by air , which disrupted the small amount of remaining Japanese coastal sea traffic . On 26 July 1945 , the President of the United States Harry S. Truman , the Chairman of the Nationalist Government of China Chiang Kai-shek and the Prime Minister of Great Britain Winston Churchill issued the Potsdam Declaration , which outlined the terms of surrender for the Empire of Japan as agreed upon at the Potsdam Conference . This ultimatum stated that , if Japan did not surrender , it would face " prompt and utter destruction . " On 6 August 1945 , the US dropped an atomic bomb on the Japanese city of Hiroshima in the first nuclear attack in history . In a press release issued after the atomic bombing of Hiroshima , President Harry S. Truman warned Japan to surrender or " expect a rain of ruin from the air , the like of which has never been seen on this earth . " Three days later , on 9 August , the US dropped another atomic bomb on Nagasaki , the last nuclear attack in history . More than 140,000 – 240,000 people died as a direct result of these two bombings . The necessity of the atomic bombings has long been debated , with detractors claiming that a naval blockade and incendiary bombing campaign had already made invasion , hence the atomic bomb , unnecessary . However , other scholars have argued that the atomic bombings shocked the Japanese government into surrender , with the Emperor finally indicating his wish to stop the war . Another argument in favor of the atomic bombs is that they helped avoid Operation Downfall , or a prolonged blockade and conventional bombing campaign , any of which would have exacted much higher casualties among Japanese civilians . Historian Richard B. Frank wrote that a Soviet invasion of Japan was never likely because they had insufficient naval capability to mount an amphibious invasion of Hokkaidō
Potsdam Conference
Potsdam Conference
Pacific War