Why do states want power?
There is a simple structural realist explanation for why states compete among themselves for
power. It is based on five straightforward assumptions about the international system. None
of these assumptions alone says that states should attempt to gain power at each other’sexpense. But when they are married together, they depict a world of ceaseless security
competition.
The first assumption is that great powers are the main actors in world politics and they
operate in an anarchic system. This is not to say that the system is characterized by chaos or
disorder. Anarchy is an ordering principle; it simply means that there is no centralized authority
or ultimate arbiter that stands above states. The opposite of anarchy is hierarchy, which is
the ordering principle of domestic politics.
The second assumption is that all states possess some offensive military capability. Each
state, in other words, has the power to inflict some harm on its neighbour. Of course, that
capability varies among states and for any state it can change over time.
The third assumption is that states can never be certain about the intentions of other
states. States ultimately want to know whether other states are determined to use force to
alter the balance of power ( revisionist states ), or whether they are satisfied enough with it
that they have no interest in using force to change it ( status quo states ). The problem, however,
is that it is almost impossible to discern another state’s intentions with a high degree of
certainty. Unlike military capabilities, intentions cannot be empirically verified. Intentions
are in the minds of decision-makers and they are especially difficult to discern.
One might respond that policy-makers disclose their intentions in speeches and policy
documents, which can be assessed. The problem with that argument is policy-makers sometimes
lie about or conceal their true intentions. But even if one could determine another
state’s intentions today, there is no way to determine its future intentions. It is impossible to
know who will be running foreign policy in any state five or ten years from now, much less
whether they will have aggressive intentions. This is not to say that states can be certain that
their neighbours have or will have revisionist goals. Instead, the argument is that policymakers
can never be certain whether they are dealing with a revisionist or status quo state.
The fourth assumption is that the main goal of states is survival. States seek to maintain
their territorial integrity and the autonomy of their domestic political order. They can pursue
other goals like prosperity and protecting human rights, but those aims must always take a
back seat to survival, because if a state does not survive, it cannot pursue those other goals.
The fifth assumption is that states are rational actors, which is to say they are capable of
coming up with sound strategies that maximize their prospects for survival. This is not to
deny that they miscalculate from time to time. Because states operate with imperfect information
in a complicated world, they sometimes make serious mistakes.
Again, none of these assumptions by themselves says that states will or should compete
with each other for power. For sure, the third assumption leaves open the possibility that
there is a revisionist state in the system. By itself, however, it says nothing about why all states
pursue power. It is only when all the assumptions are combined together that circumstances
arise where states not only become preoccupied with the balance of power, but acquire
powerful incentives to gain power at each other’s expense.
To begin with, great powers fear each other. There is little trust among them. They worry
about the intentions of other states, in large part because they are so hard to divine. Their
greatest fear is that another state might have the capability as well as the motive to attack
them. This danger is compounded by the fact that states operate in an anarchic system,
which means that there is no nightwatchman who can rescue them if they are threatened by
another country. When a state dials the emergency services for help, there is nobody in the
international system to answer the call.The level of fear between states varies from case to case, but it can never be reduced to an
inconsequential level. The stakes are simply too great to allow that to happen. International
politics is a potentially deadly business where there is the ever-present possibility of war,
which often means mass killing on and off the battlefield, and which might even lead to a
state’s destruction.
Great powers also understand that they operate in a self-help world. They have to rely on
themselves to ensure their survival, because other states are potential threats and because
there is no higher authority they can turn to if they are attacked. This is not to deny that states
can form alliances, which are often useful for dealing wit