The debacle in Iraq has reinforced the realist dictum, disparaged by idealists in the 1990s, that the legacies of geography, history and culture really do set limits on what can be accomplished in any given place. But the experience in the Balkans reinforced an idealist dictum that is equally true: One should always work near the limits of what is possible rather than cynically give up on any place. In this decade idealists went too far; in the previous one, it was realists who did not go far enough.