"In A Place Among The Nations, I drew a distinction between two kinds of peace: that between democracies and that between democracies and dictatorships. With few exceptions, democracies tend toward peace. You don't get reelected if you continually start wars and send your sons and daughters to die on foreign battlefields. Dictatorships, on the other hand, get to power by practicing aggression against their own people. So what will prevent them from practicing aggression against their neighbors?"