Polarity, stability and the balance of power

However, the fact that states are inclined to treat other states as enemies does not inevitably lead to bloodshed and open violence. Rather, neorealists, in common with classical realists, believe that conflict can be contained by the balance of power, a key concept for all realist theorists. However, while classical realists treat the balance of power as a product of prudent statecraft, neorealists see it as a consequence of the structural dynamics of the international system, and specifically, of the distribution of power (or capacities) between and among states. In short, the principal factor affecting the likelihood of a balance of power, and therefore the prospect of war or peace, are the number of great powers operating within the international system. Although neorealists believe that there is a general bias in the international system in favour of balance rather than imbalance (see To balance or to bandwagon? p. 236), world order is determined by the changing fate of great powers. This is reflected in an emphasis on polarity. Neorealists have generally associated bipolar systems with stability and a reduced likelihood of war, while multipolar systems have been associated with instability and a greater likelihood of war . This inclined neorealists to view Cold War bipolarity in broadly positive terms, as a ‘long peace’, but to warn about the implications of rising multipolarity in the post-Cold War era (discussed in more detail in Chapter 9). Realists, nevertheless, disagree about the relationship between structural instability and the likelihood of war. For so-called offensive realists, as the primary motivation of states is the acquisition of power, if the balance of power breaks down (as it tends to in conditions of multipolarity), there is a very real likelihood that war will break out (Mearsheimer 2001). Defensive realists, on the other hand, argue that states tend to prioritize security over power, in which case states will generally be reluctant to go to war, regardless of the dynamics of the international system (Mastanduno 1991)