On this day in 1945 the United States demonstrated that it was as morally bankrupt as the Nazi machine it had recently vanquished and the Soviet regime with which it was allied. Over Hiroshima, and three days later over Nagasaki, it exploded an atomic device that was the most efficient weapon of genocide in human history. The blast killed tens of thousands of men, women and children. It was an act of mass annihilation that was strategically and militarily indefensible. The Japanese had been on the verge of surrender. Hiroshima and Nagasaki had no military significance. It was a war crime for which no one was ever tried. The explosions, which marked the culmination of three centuries of physics, signaled the ascendancy of the technician and scientist as our most potent agents of death.

“In World War II Auschwitz and Hiroshima showed that progress through technology has escalated man’s destructive impulses into more precise and incredibly more devastating form,” Bruno Bettelheim said. “The concentration camps with their gas chambers, the first atomic bomb … confronted us with the stark reality of overwhelming death, not so much one’s own—this each of us has to face sooner or later, and however uneasily, most of us manage not to be overpowered by our fear of it—but the unnecessary and untimely death of millions. … Progress not only failed to preserve life but it deprived millions of their lives more effectively than had ever been possible before. Whether we choose to recognize it or not, after the second World War Auschwitz and Hiroshima became ...