Secretaries of Defense have always been acutely aware of the need to assess, balance and manage risks. They have used a variety of methods to do so, depending on the strategic environment, technology and other factors, often in the larger context of achieving objectives and living within a budget. Some of the methods have become quite well known and have been applied in other domains. Examples are systems analysis, the more general policy analysis, and the extensive use of scenarios in political–military war games and strategic planning. The US Department of Defense (DoD) has also long made use of relatively detailed operational scenarios (i.e., scenarios of particular imagined wars) to help size and shape US defense forces and also to prepare real-world war plans.

Over the last decade, newer methods have been developed that are only now catching hold. They have the potential for broad application, especially in other activities of government, such as strategic intelligence, homeland defense and counterterrorism. My primary purpose is to describe some of these new methods and explain how they are different. The discussion focuses primarily on non-nuclear examples because DoD's Cold War approach to nuclear planning and risk reduction was so unique as to be less relevant here.

Subsequent sections address the following: enduring risk-related issues faced by DoD and long-standing approaches for coping; classic Cold War methods of defense planning; new post-Cold War concepts for uncertainty-sensitive planning; and analytic methods for implementing the concepts, which include stress planning for adaptiveness.