"Some years ago, a group from several intelligence agencies was discussing the question of indications analysis and strategic warning. Reminded by an individual present that analysts who used indications methodology had correctly forecast both the North Korean attack on South Korea in 1950 and the Chinese intervention, a relative newcomer to the intelligence business said, 'Yes, but you couldn't have done a very good job, because no one believed you.' This bit of unintentional humor aptly describes much of the problem of warning intelligence. Why is it that 'no one'--a slight but not great exaggeration--believes in the indications method, despite its demonstrably good record in these and other crises which have threatened our security interests? Can the reluctance to believe be in part from the lack of understanding of the nature of indications analysis or the lack of experience with 'real' warning problems? This work was originally written in the early 1970s as a classified textbook for intelligence analysts and their supervisors and for use in intelligence courses. It was the product of some twenty-five years experience with indications and warning intelligence from the analytic standpoint. So far as I know, it was the first and perhaps still the only effort by an intelligence analyst to bring together a body of experience on the warning problem and to set forth some guidelines to assist analysts and others involved in the warning process. The examples used in the text were drawn largely from World War II and the Cold War."