This chapter examines polarity, power, ideology, domestic institutional arrangements, and the nature of political leadership shape a country’s foreign policy and diplomacy. The study of leadership, personality, and politics has been a preoccupation of social scientists for many decades, and there is a rich literature drawn from observations of a variety of political environments, from democratic to totalitarian. We can explain the similarities and continuities of Russian behavior in large part as a consequence of the international system, which conditions the foreign policies of all states. One broad generalization about Russian foreign policy that we believe to be valid is that elements of both continuity and change are always at work. Over the course of time, Russian foreign policy has exhibited many profound shifts in direction. The international system defines the broad parameters of foreign policy behavior, but obviously it cannot explain the specific decisions that determine the behavior of states in the realm of international politics.