The CIA was created as relations between the Soviet Union and its erstwhile allied partners deteriorated markedly, from wartime cooperation to mutual, simmering hostility that occasionally threatened to boil over. This hostility determined the CIA's priorities for over four decades, which could be summarised quite simply as ‘watching the bear’. The agency's main target was the USSR. The agency's objectives were to observe, assess and determine Soviet capabilities and intentions. Its role was to provide the US policy and military community with information and analysis that would allow them to form effective policies and to avoid surprise. This was a big task. Several studies have delved into the scale of the challenges the CIA faced, and how it set out to resolve them. Many of these studies have been produced by the CIA or former officers to illustrate, and occasionally defend, their record. The complexity and scale of the undertaking has often been understated by those who comment on the agency's record; this is a mistake. The CIA, and Western intelligence in general, faced an extremely difficult task in the early years of the Cold War, particularly in attempting to gain insights into the Soviet leadership, its deliberations, and what they intended to do. Joseph Stalin's Soviet Union was, in several if not most respects, a secret state.

In the absence of concrete intelligence from the Soviet Union, intelligence analysts needed to form judgements based on the best, although almost inevitably incomplete, information that they possessed at the time, as well as their expertise and key assumptions about Soviet policy. Observers often suspected that the conclusions of some assessments were more than a little reliant on a degree of Kremlinology (see the chapter in this volume on the end of the Cold War). But to assume so in general would be a disservice to the complicated work that underpinned the CIA's analyses. The analysts’ task became a highly specialised one, requiring a large number of deep, specialist subject matter experts on all manner of Soviet weapons systems and doctrines, politics, industry, education and economics. The CIA probably amassed the greatest concentration of Soviet experts in the world. Generally, they were more successful at gauging Soviet capabilities than Soviet intentions; but the record shows that they could be extremely perceptive, and could offer policymakers in Washington insights into developments in Moscow.