History as a discipline began as a confrontation with war propaganda. In the first history book, The Peloponnesian Wars, Thucydides was careful to make a distinction between leaders' accounts of their actions and the real reasons for their decisions.

The European history of the twentieth century shows us that societies can break, democracies can fall, ethics can collapse, and ordinary men can find themselves standing over death pits with guns in their hands. It would serve us well today to understand why.

The American and British soldiers who liberated the dying inmates from camps in Germany believed that they had discovered the horrors of Nazism. The images their photographers and cameramen captured of the corpses and the living skeletons at Bergen-Belsen and Buchenwald seemed to convey the worst crimes of Hitler...this was far from the truth. The worst was in the ruins of Warsaw, or the fields of Treblinka, or the marshes of Belarus, or the pits of Babi Yar.