Many analysts are convinced that they understand how arms races work. However, very few arms race studies rest upon a disciplined use of historical data, or upon a willingness to consider seriously more than one or two of the more prominent candidates for the role of the driving factor in an arms race. This article suggests that any analysis of the dynamics of the nuclear arms race cannot afford to neglect the operation of the following factors: inter-state action-reaction processes; inter-armed service action-reaction processes; intra-armed service action-reaction processes; bureaucratic political games; the very individual structures and processes of each political system; military-industrial complexities; foreign policy goals and strategies: and finally, technological innovation. Synergistic combinations of the operation of the forementioned factors produce and sustain what we term arms races. Policy prescription for arms control, if it is to be relevant, must rest upon a deep understanding of the processes to be controlled. An appreciation of the true complexity of arms race phenomena is one important intellectual step towards the ability to control.