Mao declared the Revolution over in 1969, but the Revolution's active phase would last until at least 1971, when Lin Biao, accused of a botched coup against Mao, fled and died in a plane crash.
President Truman had the urge to use the atomic bomb against Japan because the American casualties would continuously rise unless the Empire of Japan surrenders. The thing that would make Japan surrender would be a cataclysmic event, and the bombing of Hiroshima and Nagasaki happened.
