The tools of American statecraft—defense, diplomacy, foreign and security assistance, homeland security and intelligence—are rarely examined together. Adams and Williams fill this gap by examining how these tools work, how they are planned for, and how they are budgeted. Seeing policy through the lens of the budget can help decision makers and ordinary citizens discern the genuine priorities of national leaders from the oftentimes illusory ones portrayed in rhetoric. Simply put, policies and strategies cannot be carried out without a corresponding allocation of resources. Buying National Security weaves a tapestry around the institutions, organizations, tools, and processes that support planning and resource allocation across the breadth of the American national security enterprise. The authors analyze the planning and resource integration activities across agencies of the Executive branch as well as examine the structure and processes the Congress uses to carry out its national security oversight and budgetary responsibilities. Finally, they review the adequacy of the current structures and process and evaluate proposals for ways both might be reformed to fit the demands of the 21st century security environment.