No conflict in recorded history transformed the globe as thoroughly as World War II. Cities were obliterated; national borders altered; revolutionary and, in some cases, fearsome military, medical, communication and transportation technology invented; and , of course, tens of millions were killed — the majority of them civilians. Simply put, the world of August 1945, when the war ended, bore little resemblance to that of September 1939, when Nazi Germany invaded Poland.
NOTE: This story and some of the images in the gallery originally appeared, in substantially different form, on an earlier incarnation of LIFE.com. One scene shared by all of the 20th century’s bloodiest conflicts might have been lifted straight from The Road Warrior , or a Beckett play: spectral landscape; buildings obliterated; blasted trees; lifeless wasteland. The photographs in this gallery, for instance — pictures that starkly reference every bleak, war-battered panorama from Verdun to Iwo Jima to Chosin Reservoir to Pork Chop Hill — were made in September, 1945, in Hiroshima and Nagasaki, Japan. But far from chronicling the aftermath of a sustained, slogging campaign, these images — none of which were published in LIFE magazine — depict the devastation produced in a few unspeakably violent seconds.