Donnelly (2005, p.29) stated ‘Realist theory is the oldest and most frequently adopted theory of international relations.’ Most realist work since the 1970’s has been relatively structural, largely as a result from the influence of Waltz’s ‘theory of international politics’ (Donnelly, 2005, p.35) When it comes to structural realists, there is a significant divide, disputing the underlying question, how much power is enough? Defensive realists like Kenneth Waltz (1979) maintain that it is unwise for states to try to maximize their share of world power, because the system will punish them if they attempt to gain too much power. The pursuit of hegemony, they argue, is especially reckless. Offensive realists like John Mearsheimer (2001) take the opposite view; they maintain that it makes good strategic sense for states to gain as much power as possible and, if the circumstances are right, to pursue hegemony. With the demise of the ‘Soviet threat’, a world no longer divided along strategic bipolar lines has been formed. (Lazar and Lazar, 2006) After collapsing the Soviet Union, it can be said America articulated unipolar global hegemony. Conversely, many economists have predicted a change in the balance of power with the rise of China increasing. It would seem the world is gravitating towards multipolar centres of power. Furthermore, an article in The Economist (2011) predicted China to be the global economic superpower by 2030. With the threat of China’s growth being a potential danger for US hegemony, the question arises to which structural realist theory offers the best guide to US policy makers; Waltz’s defensive realism or Mearsheimer’s offensive realism?
With the end of the Cold War and the collapse of the Soviet Union many realists argue that unipolarity has arrived (Wohlforth, 1999, p.9). The