This thesis provides an analysis of the proposed and potential security functions of a United States National Missile Defense system and determines what implications the construction of such a system would have on current and future U.S.-Russian arms control agreements. This research is critical for understanding the evolution, both domestically and internationally, of ballistic missile defense systems and their link to nuclear strategy and arms control. This thesis will also explore the policy debates and political trends in both the United States and Russia concerning U.S. NMD, in an attempt to better explain each country's position. Compromise between the two countries on arms control issues involving both offensive and defensive systems is only possible if post-Cold War realities are accepted. The current arms control regime that governs both offensive and defensive systems is based on a political and military reality that no longer exists.