Bloodlands: Europe Between Hitler and Stalin by Timothy Snyder Basic Books, 524 pages, $29.95 Stalin's Genocides by Norman M. Naimark Princeton University Press, 163 pp., $26.95

Once, in an attempt to explain the history of his country to outsiders, the Polish poet Czesław Miłosz described the impact of war, occupation, and the Holocaust on ordinary morality. Mass violence, he explained, could shatter a man’s sense of natural justice. In normal times,

had he stumbled upon a corpse on the street, he would have called the police. A crowd would have gathered, and much talk and comment would have ensued. Now he knows he must avoid the dark body lying in the gutter, and refrain from asking unnecessary questions….

Murder became ordinary during wartime, wrote Miłosz, and was even regarded as legitimate if it was carried out on behalf of the resistance. In the name of patriotism, young boys from law-abiding, middle-class families became hardened criminals, thugs for whom “the killing of a man presents no great moral problem.” Theft became ordinary too, as did falsehood and fabrication. People learned to sleep through sounds that would once have roused the whole neighborhood: the rattle of machine-gun fire, the cries of men in agony, the cursing of the policeman dragging the neighbors away.

For all of these reasons, Miłosz explained, “the man of the East cannot take Americans [or other Westerners] seriously.” Because they hadn’t undergone such experiences, they couldn’t seem to fathom what they meant, and couldn’t seem to imagine how they had happened either. “Their resultant lack of imagination,” he concluded, “is appalling.”1

But Miłosz’s bitter analysis did not go far enough. Almost sixty years after the poet wrote those words, it is no longer enough to say that we Westerners lack imagination. Timothy Snyder, a Yale historian whose past work has ranged from Habsburg Vienna to Stalinist Kiev, takes the point one step further. In Bloodlands, a brave and original history of mass killing in the twentieth century, he argues that we still lack any real knowledge of what happened in the eastern half of Europe in the twentieth century. And he is right: if we are American, we think “the war” was something that started with Pearl Harbor in 1941 and ended with the atomic bomb in 1945. If we are British, we remember the Blitz of 1940 (and indeed are commemorating it energetically this year) and the liberation of Belsen. If we are French, we remember Vichy and the Resistance. If we are Dutch we think of Anne Frank. Even if we are German we know only a part of the story.

Snyder’s ambition is to persuade the West—and the rest of the world—to see the war in a broader perspective. He does so by disputing popular assumptions about victims, death tolls, and…