More than a million non-combatants in both Germany and Japan. And twenty million people in the Soviet Union, most of them civilians. These civilians were targeted because they helped sustain the war, mostly through industrial and agricultural production. In a total war, when a nation is at war, not just its army, there's no such thing as a non-military target. From the firebombing of Dresden, to Tokyo, to Hiroshima, the line between soldier and civilian blurred. And then, of course, there is the Holocaust, which horrifies us because the elements of Western progress, record-keeping, industrial production, technology, were used to slaughter millions. World War II saw modern industrial nations, which represented the best of the Enlightenment and the Scientific Revolution, descend into once unimaginable cruelty.