Neorealism

From classical realism to structure

Classical realists such as Hans Morgenthau (1948) traced the struggle for power in international politics to a human nature that seeks power. In Man, the State, and War (1959), Kenneth Waltz sorted the causes of war into the individual (first image), the state (second image) and the international system (third image), and in Theory of International Politics (1979) he built a parsimonious systemic theory around the third image. He defined the structure of the international system by three elements. First, its ordering principle is anarchy, not hierarchy. Second, because under anarchy every state must provide for its own survival, states are functionally similar "like units." Third, what varies among units is only the distribution of capabilities, or polarity. Major changes in international politics are therefore explained by changes in the number of great powers.

Core propositions

Under anarchy states inhabit a self-help system, and their ultimate goal is not maximizing power but survival and security. They therefore tend to balance against threatening states, internally by arming or externally through alliances, and balances of power form repeatedly even when no one intends them. Waltz also argued that cooperation is hard because states worry less about absolute gains than about relative gains, whether others gain more (Grieco, 1988). Waltz (1964) held that a bipolar system like the Cold War, with two great powers facing each other, is more stable than a multipolar one because miscalculation is less likely. Stephen Walt (1987) refined this with balance-of-threat theory, arguing that states balance against threats rather than power alone. The security dilemma (Jervis, 1978) is also central to this framework.

Branches and critiques

Neorealism later split in two. Waltz's defensive realism stresses the status quo, holding that overexpansion provokes balancing coalitions and is self-defeating. John Mearsheimer's (2001) offensive realism holds that great powers seek as much power as possible, ultimately regional hegemony, to survive, and predicted that China's rise would not be peaceful. Neoclassical realism, named by Gideon Rose (1998), argues that structural pressures are filtered through leaders' perceptions and domestic institutions into foreign policy. Critics abound. Neorealism was faulted for failing to predict the peaceful end of the Cold War; neoliberal institutionalists such as Keohane (1986) countered that institutions enable cooperation; and Alexander Wendt (1992) argued that "anarchy is what states make of it," with structure made of shared ideas rather than material power. Wohlforth (1999) judged the post–Cold War unipolar system to be stable.

FAQ

What is neorealism in simple terms?

Because there is no government above states, each country must look after its own survival, so states inevitably compete and balance one another's power.

How does it differ from classical realism?

Classical realism locates the cause of power struggles in human nature, whereas neorealism locates it in the structure of an international system with no central authority and in the distribution of power.

Sources reviewed: 2026-10-26

References

1. Waltz, K. N. (1979). Theory of International Politics. Reading, MA: Addison-Wesley.
2. Waltz, K. N. (1959). Man, the State, and War. New York: Columbia University Press.
3. Waltz, K. N. (1964). The stability of a bipolar world. Daedalus, 93(3), 881–909.
4. Mearsheimer, J. J. (2001). The Tragedy of Great Power Politics. New York: W. W. Norton.
5. Mearsheimer, J. J. (1990). Back to the future: Instability in Europe after the Cold War. International Security, 15(1), 5–56.
6. Walt, S. M. (1987). The Origins of Alliances. Ithaca: Cornell University Press.
7. Grieco, J. M. (1988). Anarchy and the limits of cooperation. International Organization, 42(3), 485–507.
8. Keohane, R. O. (Ed.). (1986). Neorealism and Its Critics. New York: Columbia University Press.
9. Wendt, A. (1992). Anarchy is what states make of it. International Organization, 46(2), 391–425.
10. Morgenthau, H. J. (1948). Politics Among Nations. New York: Alfred A. Knopf.
11. Rose, G. (1998). Neoclassical realism and theories of foreign policy. World Politics, 51(1), 144–172.
12. Jervis, R. (1978). Cooperation under the security dilemma. World Politics, 30(2), 167–214.
13. Wohlforth, W. C. (1999). The stability of a unipolar world. International Security, 24(1), 5–41.