Mearsheimer's Offensive Realism
John Mearsheimer theorized that states seek maximum power to ensure survival in an anarchic international system.
Updated April 23, 2026
How It Works in Practice
Mearsheimer's Offensive Realism argues that in the anarchic international system—where no central authority governs states—countries must prioritize their own survival by striving to maximize their power. Unlike defensive realism, which suggests states seek enough power for security, offensive realism posits that states aim to become the dominant power to deter any threats effectively. This compels states to constantly assess their relative power and pursue aggressive policies such as military buildups, strategic alliances, or territorial expansion to prevent rivals from challenging them.
Why It Matters
Understanding offensive realism is crucial for interpreting international relations and state behavior. It explains why great powers often engage in competition or conflict despite the risks involved—because in a world without overarching authority, power is the ultimate currency for survival. This theory helps policymakers anticipate actions by other states and design strategies that consider the relentless pursuit of power as a driving force behind diplomacy, alliances, and conflicts.
Offensive Realism vs Defensive Realism
While both theories agree that the international system is anarchic and states seek security, they differ in the extent of power states desire. Defensive realism suggests that states are primarily security maximizers, seeking just enough power to ensure safety, avoiding unnecessary conflict. Offensive realism, by contrast, sees states as power maximizers, believing that only by achieving hegemony or regional dominance can a state guarantee its survival. This leads to more aggressive foreign policies in offensive realism compared to the more cautious approach in defensive realism.
Real-World Examples
Mearsheimer points to the Cold War as a prime example, where both the United States and the Soviet Union sought to expand their influence and military capabilities aggressively to prevent the other from achieving dominance. Similarly, China’s recent military modernization and assertive policies in the South China Sea can be interpreted through the lens of offensive realism, as Beijing aims to secure regional hegemony and deter rival powers.
Common Misconceptions
A frequent misunderstanding is that offensive realism advocates for constant war or conflict. However, the theory does not claim war is inevitable but that states will take all necessary measures to maximize power, which can include diplomacy and alliances. Another misconception is that offensive realism assumes states act irrationally; instead, it views states as rational actors pursuing their survival through power maximization under uncertainty.
Example
During the Cold War, the United States and the Soviet Union engaged in an arms race reflecting offensive realism's prediction of power maximization to ensure survival.