This chapter examines the conventional military relationship between North Atlantic Treaty Organization (NATO) and the Warsaw Pact and identifies critical variables that NATO should seek to manipulate through arms control. Identifying the principal characteristics of the military problem in Europe is typically a product of quantitative assessments of the military balance: counting the forces, units, equipment, and other measurable indicators of military power. The limitations of bean counting become especially acute when its application extends beyond the world of military force planning and analysis to the more politicized world of arms control policy. The implication of the methodological bias is that even small differences in assumptions about critical and inherently subjective input variables can lead to dramatically different results. NATO's principal vulnerability, therefore, seems to be to a rapid breakthrough of Soviet combined arms forces, coupled with the destruction and disruption of key command and control and air defense assets.