Most definitions of politics involve power. Most international interactions are political or have rami‐ fications for politics. Thus, it is not surprising that power has been prominent in discussions of international interaction from Thucydides to the present day. The long history of discussions of the role of power in international relations, however, has failed to generate much agreement. Scholars disagree not only with respect to the role of power but also with respect to the nature of power. Hans J. Morgenthau (1964: 27n) suggests that ‘the concept of political power poses one of the most difficult and controversial problems of political science.’ Kenneth N. Waltz (1986: 333) notes that power is a key concept in realist theories of international politics, while conceding that 'its proper definition remains a matter of controversy.’ And Robert Gilpin describes the concept of power as 'one of the most troublesome in the field of international relations' (1981: 13) and suggests that the 'number and variety of definitions should be an embarrassment to political scientists' (1975: 24). There is, however, widespread consensus among international relations scholars on both the necessity of addressing the role of power in international interactions and the unsatisfactory state of knowledge about this topic (Guzzini, 2000; Barnett and Duvall, 2005; Berenskoetter and Williams, 2007).
Although it is often useful to distinguish among such power terms as power, influence, control, coercion, force, persuasion, deterrence, compellence, inducement and so on, it is possible to identify common elements underlying all such terms. Robert A. Dahl (1957) has suggested that underlying most such terms is the basic intuitive notion of A causing (or having the ability to cause) B to do something that B otherwise would not do. (In the discussion that follows, 'A' refers to the actor having or exercising influence; while 'B' refers to the actor being, or potentially being, influenced.) Although alternative definitions of power abound, none rivals this one in widespread acceptability. In the following discussion, the term 'power' will be used in a broad generic sense that is interchangeable with such terms as 'influence' or 'control' unless otherwise indicated. This usage is not intended to deny the validity or the utility of distinguishing among such terms for other purposes.
POWER AND THE STUDY OF INTERNATIONAL POLITICS International politics has been defined in terms of influencing 'major groups in the world so as to advance the purposes of some against the opposition of others' (Wright, 1955: 130). Although the term 'power politics' has unsavory connotations for some, such a definition implies that the term is redundant (Carr, [1939]1946; Morgenthau, [1948]1960; Sprout and Sprout, 1945; Spykman, 1942; Wright, 1955). From this perspective, all politics is power politics in the sense that all politics involves power. This is not to say that politics is only about power. Traditionally, the study of international politics assumed the existence of national states with conflicting policies, placing a high value on maintaining their independence, and relying primarily on military force. The states with the most military power were designated 'Great Powers', and the 'game' of international politics was 'played' primarily by them (Spykman, 1942; Sprout and Sprout, 1945, 1962; Wight, 1946). Noting that only a few states possessed the military capabilities to support their foreign policies effectively, an influential text in the 1930s averred that 'these alone constitute the Great Powers' (Simonds and Emeny, 1937: 28.1 In the eighteenth century, 'the power of individual states was conceived to be susceptible of measurement by certain well‐defined factors' (Gulick, 1955: 24), including population, territory, wealth, armies and navies. In the ensuing years, this approach evolved into the 'elements of national power' approach to power analysis reflected in Hans J. Morgenthau's influential textbook Politics Among Nations ([1948] 1960 see also Sprout and Sprout, 1945). States were depicted as seeking to maximize power relative to each other, thus producing a 'balance of power' or as seeking to produce a balance of power (Claude, 1962; Gulick, 1955; Haas, 1953; Morgenthau [1948] 1960). Each version of balance of power theory shared the assumption that it was possible to add up the various elements of national power, sometimes called 'power resources' or 'capabilities', in order to calculate the power distribution among the Great Powers. Modern versions of this approach are found in Waltz's Theory of International Politics (1979) and John J. Mearsheimer’s The Tragedy of Great Power Politics (2001). THE POWER ANALYSIS REVOLUTION The 'elements of national power' approach depicted power as a possession or property of states. This approach was challenged during the last half of the twentieth century by the 'relational p