Rationalization, standardization, and interoperability (RSI) has been an important issue in NATO throughout the 1970s. Increasingly, national political and military leaders have expressed the concern that doctrine, procedures, and materiel should be harmonized more effectively as one means of counterbalancing the Warsaw Pact. However, in the past decade RSI initiatives have been largely unsuccessful. Weapons standardization in NATO depensupon the scope and degree of ideological advocacy for the collaborative security imperative and the influence of economic competition in arms production and sales among the members of the Alliance. An analysis of the disparate views of the member-states and of threecase studies—the MX-1 tank treads, the ribbon bridge, and ROLAND II—indicates that ideological advocacy has been high among international and national elites (if not among subnational elites), but that the increased economic competition following the rise of European defense industries during the last fifteen years has exacerbated national policy differences and decreased the prospects for RSI success.