Domestic Politics, Foreign Policy, and Theories of International Relations

▪ Abstract A significant and growing literature on international relations (IR) argues that domestic politics is typically an important part of the explanation for states' foreign policies, and seeks to understand its influence more precisely. I argue that what constitutes a “domestic-political” explanation of a state's foreign policy choices has not been clearly elaborated. What counts as a domestic-political explanation is defined by opposition to systemic or structural explanations. But these may be specified in several different ways—I spell out two—each of which implies a different concept of domestic-political explanations. If a systemic IR theory pictures states as unitary, rational actors, then a domestic-political explanation is one in which domestic-political interactions in at least one state yield a suboptimal foreign policy relative to some normative standard. Or, if a systemic IR theory pictures states as unitary, rational actors and also requires that attributes of particular states not enter the explanation, then a domestic-political explanation is any one that involves state characteristics other than relative power. Implications of each approach are developed, and examples from the literature are provided. I also address the question of whether there is a sharp distinction between a “systemic theory of international politics” and a “theory of foreign policy,” arguing that there is an important and natural sense in which they are the same.