Which major theory of international relations—neorealism, liberalism, or constructivism—best explains states' weapons procurement strategies? This article addresses that question by examining the case of the Federal Republic of Germany (FRG) during the Cold War. Through an in-depth analysis of the FRG's armaments strategy from the time the country was admitted into the North Atlantic Treaty Organization in 1955 until the early 1970s, the article demonstrates that although ideas and external security concerns did play a role, economic concerns won out more often than not. IR scholars must therefore account for a variety of factors when attempting to explain the FRG's weapons procurement strategy during this period. Neorealism, liberalism, and constructivism are useful in thinking about West Germany's purchases of weapons, but none of the three theories is adequate on its own.