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 with
dangerous adversaries. In the final analysis, however, states have no choice but to put their
own interests ahead of the interests of other states as well as the so-called international
community.
Fearful of other states, and knowing that they operate in a self-help world, states quickly
realize that the best way to survive is to be especially powerful. The reasoning here is
straightforward: the more powerful a state is relative to its competitors, the less likely it is
that it will be attacked. No country in the Western Hemisphere, for example, would dare
strike the USA, because it is so powerful relative to its neighbours.
This simple logic drives great powers to look for opportunities to shift the balance of
power in their favour. At the very least, states want to make sure that no other state gains
power at their expense. Of course, each state in the system understands this logic, which
leads to an unremitting competition for power. In essence, the structure of the system
forces every great power – even those that would otherwise be satisfied with the status
quo – to think and act when appropriate like a revisionist state.