Neorealism

The structure of the international system, not human nature, explains how states behave.

Neorealism, also called structural realism, keeps realism's starting point and changes its explanation. Kenneth Waltz argued in Theory of International Politics that you do not need claims about human nature or the character of particular governments to account for the recurring patterns of international life. The structure of the system does the work: it is anarchic, its units perform similar functions, and they differ mainly in how capabilities are distributed among them.

From that structure follow the theory's expectations. States worry about relative rather than absolute gains, because an advantage that helps a rival more than it helps you is a loss in a system where you may one day have to face them. Balances recur whether or not any statesman intends them. The number of great powers matters: Waltz held bipolarity to be more stable than multipolarity because there are fewer relationships to misjudge.

The tradition divides over how much power is enough. Defensive realists argue that states seek an appropriate amount and that overexpansion is punished. John Mearsheimer's offensive realism argues that no state can ever be certain of another's intentions, so the only safe amount of power is as much as possible, and regional hegemony is the rational goal.

Key thinkers

Kenneth Waltz, John Mearsheimer, Stephen Walt, Robert Jervis, Joseph Grieco.

Core concepts

structural realism, polarity, relative gains, balance of threat, offensive and defensive realism, distribution of capabilities.

Neorealism applied to 45 historical events

Every event on Theoria is read through all six theories. These are the readings Neorealism gives, moment by moment. Open one to compare it against the other five, or explore them on the interactive map.

The other theories