The United States must succeed in Iraq, for failure means an unacceptable loss of prestige and freedom for us--and a much less-secure world for everybody else. Our success in Iraq will establish a foothold for modernity in the Middle East and deal a stinging defeat to Islamism, which will increase our credibility in the region (and beyond) and offer the model for improvement. It follows, ultimate success vindicates the decision to invade and remake Iraq.