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the aggressor would find unacceptable and, especially, a promise that success of the aggressive action will be denied. Sometimes the dissuasion will involve inducements to change behavior, and reassurance that the "deterree" will not be attacked.

The approach to deterrence will involve a range of activities on our part, in the political, diplomatic, economic, and military spheres, independently or in concert. A strategy of deterrence therefore could be concerned with much of the threatening or violent activity that can now affect the United States on the international scene, and deterring such activity can encompass almost all of U.S. foreign policy actions. However, the potential or actual use of effective military force will underlie all deterrence efforts-—even deterrence of actions in the economic and political areas should they appear sufficiently threatening to our security.

ENDURING PRINCIPLES IN DETERRENCE STRATEGY

Despite the changed international climate and the diffuse quality of our current security concerns, many of the principles that supported earlier deterrence strategy endure. They include the following:

• National interests. We must define our national interests so as to know whom we wish to deter from doing what to whom, by what means, and under what circumstances. In doing so, we must recognize that interests change with circumstances—while we might find peaceful evolution of international relationships and governments in areas of national interest acceptable, violent change in those relationships through invasion, sustained terrorist attack, or severe internal conflict can pose serious threats to our interests and those of our allies that must be deterred.

• Credibility. Deterrence can succeed only if the combination of threat and incentives is credible. This requires demonstrated political will, as evidenced in the willingness to sustain economic costs, to endure human casualties, and to take risks in support of the deterrence efforts. The military force invoked as part of the deterrence action must be clearly capable of achieving the promised military objectives.

• Communication and perceptions. The actions desired from the object of deterrence—the "deterree"—and consequences of the failure of deterrence must be communicated clearly, in terms the recipient of the communications will understand. Warnings, promises, and communications must be suited to the value system of the deterree, and must be acceptable within the value systems of the United States and its actual or potential coalition partners. They must be commensurate with values the deterree holds dear, and with the deterree's political as