The Causes of War 271can we study the causes of war systematically, when the causes often seem idiosyn-
cratic? To identify patterns and variables that might explain not just one war but war
more generally, international relations scholars have found it useful to consider causes
of war at the three levels of analy sis Kenneth Waltz identified in Man, the State, and
War^8 — the individual, the state, and the international system.
the Individual: realist and liberal Interpretations
Both the characteristics of individual leaders and the general attributes of people (dis-
cussed in Chapter 6) have been blamed for war. Some individual leaders are aggressive
and bellicose; they use their leadership positions to further their causes. Others may
be nonconfrontational by nature, perhaps avoiding commitments that might deter
aggression, making war more likely. Thus, according to some realists and liberals, war
occurs because of the personal characteristics of major leaders. It is impossible, how-
ever, to prove the general veracity of this position. Would past wars have occurred had
dif er ent leaders— perhaps more pacifistic ones— been in power? What about wars
that nearly happened but did not happen, due to the intervention of a charismatic
leader? As we can see, the impact of individual leaders on war is difficult to generalize.
We can identify some wars in which individuals played a crucial role, but if we are
looking for a general explanation— one that might guide us across dif er ent periods
or cultures— explanations based on individual characteristics or human nature will
prove insufficient.
If the innate character flaws of individuals do not cause war, is it pos si ble that lead-
ers, like all humans, are subject to misperceptions that might lead to war? According to
liberals, misperceptions by leaders— seeing aggressiveness where it may not be intended,
attributing the actions of one person to a group— can indeed lead to the outbreak of
war. Unlike individual characteristics such as charisma or the possession of extreme
views, we can generalize about the human tendency toward misperception. Several types
of misperceptions may lead to war. One of the most common is exaggerating the
adversary’s hostility, believing that it is more hostile than it may actually be or that it
has greater military or economic capability than it actually has. This tendency may lead
a state to build up its own arms or seek new allies, which its actual or potential rivals,
in turn, may view as hostile acts. Misperceptions thus spiral, leading to costly arms
races, new alliances, and potentially to war. The events leading up to World War I are
often viewed as such a conflict spiral.
Beyond the characteristics of individual leaders, perhaps factors par tic u lar to the
masses lead to the outbreak of war. Some realist thinkers— Saint Augustine and Rein-
hold Niebuhr, for example— take this position. Augustine wrote that every act is an
act of self- preservation on the part of individuals. For Niebuhr, the link goes even
deeper; the origins of war reside in the depths of the human psyche.^9 This approach is