This book was the result of emigration across disciplinary boundaries. The point of departure was cognitive psychology and its philosophical underpinnings, a realm of meticulous experimental observation and highly generalized interpretative reasoning. The eventual destination was international security policy whose reigning doctrine�the concept of deterrence�was derived from an idealized vision of human mental operations that basic psychology would suggest is regularly violated in everyday life. In the initial stages of this journey I was astonished that security policies of such consequence could be constructed in apparent ignorance, or at any rate cheerful defiance, of what I understood to be some of the more important facts about how the human mind actually works. Since that remarkable instrument provides the foundation of all organized behavior, it seemed to me, its known features should inform any activity as serious as the deployment of nuclear weapons.
In the course of writing the book and thereafter I became more accustomed to prevailing security logic and more tolerant of the role it has come to play in the management of inherently dangerous technology. The chief advantage of the logic of deterrence is that so many people are readily willing to believe in it and to accept its asserted requirements. If the underlying suppositions of the deterrence doctrine are difficult to reconcile with major characteristics of human behavior, they do nonetheless reflect how most people prefer to understand the business of determining threat and devising protection. Organizing ideas that can command widespread acceptance are an essential element of any coherent policy Nuclear weapons and the broader issues of international security definitely require reliably coherent policies.
John Steinbruner is director of the Center for International and Security Studies at Maryland.