Laying out a detailed rationale for action against Iraq, Kaplan and Kristol make clear that the controversy over it is largely a war of competing ideas about America’s role in the world. They provide the first comprehensive explanation of the strategy of “preemption” guiding the Bush administration in dealing with this crisis, and show that American foreign policy for the 21st century is being forged in the crucible of our response to Saddam Hussein. The Iraq war means the end of Saddam, and also the beginning of a new era in American foreign policy. Kaplan and Kristol offer guidance for the path ahead.