It now appears likely that the invasion of Iraq will prove to be a seminal event in the evolution of international security generally. Legal order has evidently collapsed throughout the country, and the occupying forces have not been able to control the resulting pattern of predatory violence. The central reason is that the United States forfeited at the outset the critical asset of legitimacy necessary to establish and maintain consensual rule, and its continued presence undermines the indigenous institutions it is attempting to nurture. Similar breakdowns have occurred in other parts of the world, and the consequences have been tolerated over extended periods of time. Because of timing, location and the entanglement of the United States, however, intractable violence in Iraq can be expected to have much stronger global resonance. American forces alone are not likely to be able to master the situation but neither can they be withdrawn without intensifying internal violence and extending it into an already volatile region. The potential consequences of that dilemma are ominous, but for that reason the situation presents opportunity as well as danger. Calamity is sometimes a catalyst for greater wisdom.