More than a thousand radio addresses drafted by Ronald Reagan in the 1970s, between his terms as governor of California and president of the United States, were recently published. These addresses, along with related writings from 1951 to 1985, reveal longstanding, consistent beliefs about a wide variety of topics in international relations and foreign policy. In particular, the writings presage specific arms control policies that were implemented in Reagan's first term as president. This article reassesses some of these policies in light of the newly released addresses. The article draws on experimental psychology to discuss a specific judgmental bias, availability, which makes particular beliefs more accessible, and then examines the five specific beliefs that influenced Reagan in his approach to arms control negotiations. In each case the article shows how these beliefs affected policy outcomes and choices.