The dramatic changes that Mikhail Gorbachev has brought to the content and conduct of Soviet foreign policy in the form of "new political thinking" have profound implications for the West. This paper analyzes Gorbachev's policies on national security issues. It includes a brief overview of new political thinking, including its goals, origins, and the elements it comprises; discusses the emerging role of Soviet civilian defense analysts in the formulation of Soviet defense policy; and considers both the strategic nuclear and theater conventional dimensions of "reasonable sufficiency." It also analyzes in depth the particularly contentious issues that civilian defense analysts and the professional military are currently debating. It concludes with some observations about the implications of new political thinking for the West.