During the summer of 1945, as millions of U.S. servicemen planned for two massive invasions of Japan and several thousand others were engaged in the Manhattan Project to develop the atomic bomb, a handful of Army officers had another plan to end the war.
Major General William N. Porter, chief of the Army's Chemical Warfare Service, orchestrated a scheme to kill an estimated five million Japanese with poison gas. A document kept under wraps for five decades, the 29-page, "A Study of the Possible Use of Toxic Gas in Operation Olympic," details the ultimate attack.
Strategic bombers (B-29s and B-24s) would drop 56,583 tons of poison-gas bombs in the first 15 days of what the document called the "initial gas blitz." And they were to drop another 23,935 tons of gas bombs every month that the war dragged on or until all targets had been hit.