Offensive Realism

Background and assumptions

Morgenthau's (1948) classical realism located the pursuit of power in human nature, while Waltz's (1979) neorealism held that the anarchic structure of the international system constrains state behavior. Waltz saw states as seeking above all survival and security, and regarded excessive expansion as dangerous because it provokes balancing by others, a position that developed into defensive realism. Mearsheimer (2001) drew a different conclusion from the same structural starting point. He set out five assumptions: the international system is anarchic, great powers possess offensive capabilities, states can never be certain of others' intentions, survival is the primary goal, and states are rational actors. Under these conditions no one guarantees a state's safety, so the surest way to survive is to become as powerful as possible, that is, to become the hegemon.

Regional hegemony and offshore balancing

Mearsheimer argued that the stopping power of water makes global hegemony virtually impossible. The realistic goal of a great power is therefore to become the hegemon in its own region while preventing rival hegemons from emerging elsewhere. He saw the United States as the only modern great power to have achieved regional hegemony, in the Western Hemisphere, and described it as acting as an offshore balancer, passing the buck to regional states when potential hegemons appeared in Europe or Asia and intervening directly only when necessary. Mearsheimer (1990) also predicted that the end of Cold War bipolarity would make Europe less stable. Zakaria (1998) analyzed the U.S. case to show that a state's external interests and influence expand as its power grows, and Labs (1997) supported offensive realism by showing that states at war expand their war aims when opportunities arise.

Debates and critiques

Defensive realists challenged offensive realism. Jervis (1978) argued that the intensity of the security dilemma depends on whether offense or defense has the advantage and whether the two can be distinguished, and Glaser (1994) contended that cooperation can be a rational form of self-help even under anarchy. Taliaferro (2000) restated the logic of defensive realism, holding that expansion often backfires. Snyder (2002) judged that Mearsheimer's theory, while emphasizing power maximization, does not fully account for the caution states actually show in their calculations. Mearsheimer predicted that a continually rising China would seek regional hegemony in Asia and compete intensely with the United States; Kirshner (2012) criticized this prediction from a classical realist standpoint as overly deterministic. Mearsheimer's (2014) argument locating the cause of the Ukraine crisis in Western NATO expansion also sparked major controversy. The theory is treated alongside power transition theory and hegemonic stability theory as a major account of great power relations.

FAQ

What is offensive realism in simple terms?

Because there is no police force in international society to protect countries, great powers try to become as strong as possible relative to others to be safe, and ultimately seek to be number one in their own region.

How do offensive and defensive realism differ?

Both start from the anarchic structure of the international system, but defensive realism holds that states are satisfied with adequate security and that excessive expansion invites counterbalancing and backfires. Offensive realism holds that because others' intentions cannot be trusted, it is rational to maximize power and pursue hegemony when opportunities arise.

Sources reviewed: 2026-10-26

References

1. Morgenthau, H. J. (1948). Politics Among Nations: The Struggle for Power and Peace. New York: Knopf.
2. Waltz, K. N. (1979). Theory of International Politics. Reading, MA: Addison-Wesley.
3. Jervis, R. (1978). Cooperation under the security dilemma. World Politics, 30(2), 167–214.
4. Mearsheimer, J. J. (1990). Back to the future: Instability in Europe after the Cold War. International Security, 15(1), 5–56.
5. Mearsheimer, J. J. (2001). The Tragedy of Great Power Politics. New York: W. W. Norton.
6. Zakaria, F. (1998). From Wealth to Power: The Unusual Origins of America's World Role. Princeton: Princeton University Press.
7. Labs, E. J. (1997). Beyond victory: Offensive realism and the expansion of war aims. Security Studies, 6(4), 1–49.
8. Snyder, G. H. (2002). Mearsheimer's world: Offensive realism and the struggle for security. International Security, 27(1), 149–173.
9. Glaser, C. L. (1994). Realists as optimists: Cooperation as self-help. International Security, 19(3), 50–90.
10. Taliaferro, J. W. (2000). Security seeking under anarchy: Defensive realism revisited. International Security, 25(3), 128–161.
11. Kirshner, J. (2012). The tragedy of offensive realism: Classical realism and the rise of China. European Journal of International Relations, 18(1), 53–75.
12. Mearsheimer, J. J. (2014). Why the Ukraine crisis is the West's fault: The liberal delusions that provoked Putin. Foreign Affairs, 93(5), 77–89.