The Causes of War 275Yet, in virtually every case cited here, neither characteristics of the state nor state
structures sufficiently explain the causes of war and peace. This is why neorealists such
as Kenneth N. Waltz argue that we need to look for explanations at the level of the
international system.
the International system: realist and radical Interpretations
If one key issue or argument distinguishes realists from their liberal and radical critics,
it is that for realists, war is a natu ral, and hence an inevitable feature of interstate poli-
tics. War is as tragic and unpreventable as hurricanes and earthquakes. In advancing
this argument, con temporary realists tend to focus on a single description of the inter-
national system as anarchic. Such an anarchic system is often compared with a “state
of nature,” after phi los o pher Thomas Hobbes’s characterization, in which humans live
without a recognized authority, and must therefore manage their own safety by them-
selves. In his most famous book, Leviathan, Hobbes argued that whenever men live
without a common power that keeps them all in fear, they are in a condition of war:
“ every man against every man.” This state leads to constant fear and uncertainty. By
extension, because states in the international system do not recognize any authority
above them, the international system is equivalent to a state of war, and Hobbes’s
description of that state perfectly characterizes the realist view. War, Hobbes continued,
was not the same thing as battle or constant fighting. Instead, it was any tract of time in
which war remained pos si ble. Hobbes likened this situation to the relationship between
climate and weather: it may not rain every day, but in some climates, rain is much more
common than in others. Essentially, Hobbes concluded that so long as a single strong
man (or state) was not more power ful than all the others combined, human beings
would be forced to live in a climate of war.^10
According to realists then, war breaks out in the interstate system because nothing
in the interstate system prevents it. So long as there is anarchy, there will be war. War,
in such a system, might even appear to be the best course of action that a given state
can take. After all, states must protect themselves. A state’s security is ensured only
by its accumulating military and economic power. But one state’s accumulation makes
other states less secure, according to the logic of the security dilemma.
An anarchic system may have few rules about how to decide among states’ con-
tending claims. One of the major categories of contested claims is territory. For almost
all of the previous century, the Arab-Israeli dispute rested on competing territorial
claims to Palestine; in the Horn of Africa, the territorial aspirations of the Somali people
remain disputed; in the Andes, Ec ua dor and Peru have competing territorial claims;
and in the South China Sea, Japan, China, Taiwan, the Philippines, and Vietnam are