Examining the political foundations of American intelligence policy, this book develops a new theory of intelligence adaptation to explain the success or failure of major reform efforts since World War II. Durbin draws on careful case histories of the early Cold War, the Nixon and Ford administrations, the first decade after the Cold War, and the post-9/11 period, looking closely at the interactions among Congress, executive branch leaders, and intelligence officials. These cases demonstrate the significance of two factors in the success or failure of reform efforts: the level of foreign policy consensus in the system, and the ability of reformers to overcome the information advantages held by intelligence agencies. As these factors ebb and flow, windows of opportunity for reform open and close, and different actors and interests come to influence reform outcomes. Durbin concludes that the politics of US intelligence frequently inhibit effective adaptation, undermining America’s security and the civil liberties of its citizens.