The gravest decision in a democracy is the one to go to war. Describing unilateralism as the oldest doctrine in American history, Schlesinger nevertheless warns of the dangers posed by the fatal turn in US policy from deterrence and containment to preventive war. He writes powerfully about George W. Bush's expansion of presidential power and the revived Imperial Presidency (a phrase Schlesinger invented). He reminds Americans of their distinguished legacy of patriotism through dissent in wartime, calling on them to honour that tradition even in the face of their need for security. He reminds us of the inscrutability of history.