More than half a century has elapsed since the end of World War II, and it is difficult to fully comprehend the enormity of what was by far the most destructive human endeavor in history. Battles were fought on every continent and involved more than sixty countries, affecting roughly three-quarters of the world's population. The casualty figures are staggering: More than 57 million people were killed, more than half of whom were civilians. The Soviet Union alone suffered the loss of more than 21 million people. The United States, which entered the war later than the other Allies, still had roughly three hundred thousand casualties.

Beyond these general statistics, however, were hundreds, maybe thousands, of stories of crimes committed against soldiers and civilians. These included cases of prisoners of war being murdered, sent to concentration camps, and abused; and civilians herded into ghettos and exterminated...