The author attempts to review the adjustment and transformation of Americas arms control policy since the end of the Cold War, and to explore what has motivated such changes, and finally to try to better understand the relationship between Americas arms control policy and its overall security policy. The author argues that after G. W. Bush took office, the change in the understanding of American strategic security environment, the inherent flaws in arms control regimes, and the difficulty in promoting arms control regime building propelled the United States onto the path of policy adjustment, while accidental events, policy preferences of decisionmakers, and domestic political environment accelerated this process. Thus American arms control policy gradually completed the change from relying on regime building to emphasizing coalition of the willing.