What are the great debates between ‘classical’ and ‘modern’ realists? Is there any thin line of continuity between these two traditions? (2012, 20 Marks)
Classical realism, from Thucydides, Niccolò Machiavelli and Thomas Hobbes to E. H. Carr, Reinhold Niebuhr and Hans J. Morgenthau, is a philosophy of statecraft. Modern realism began with Kenneth N. Waltz‘s structural theory (1979) and branched into offensive, defensive and neoclassical variants that aim at social science. The two argue over foundations and method far more than over the picture of the world they describe.
The great debates
1. Where conflict comes from. Classical realists locate it in human nature: Morgenthau’s animus dominandi and Niebuhr’s original sin. Waltz moved it to the third image, the anarchic system. A constant human nature, he argued, cannot explain variation between peace and war.
2. How to know. Classical realism is historical, interpretive and wary of quantification. This echoes the second great debate of the 1960s, when Hedley Bull defended a classical approach against the scientific method of Morton A. Kaplan. Modern realists prefer deductive, parsimonious theory modelled on micro-economics.
3. Power as end or means. For Morgenthau, power is both end and means. For Waltz it is a means to security, and states seek to preserve their position. Modern realists then divide among themselves: John J. Mearsheimer‘s offensive realism returns to power maximisation, while defensive realists counsel restraint.
4. Ethics and the statesman. Classical realists are moralists of a tragic kind. Morgenthau made prudence the supreme political virtue, and Carr argued that pure realism is sterile without utopian purpose. Modern realism is explanatory and largely silent on ethics, and its structure pushes the statesman out of the explanation.
5. Foreign policy or international politics. Classical realism advises foreign policy directly. Waltz offered a theory of recurring international outcomes and insisted it was not a theory of foreign policy.
6. Polarity and stability. Classical realists trusted a flexible multipolar balance worked by skilled diplomacy. Waltz judged bipolarity more stable.
The line of continuity
The line is more than thin.
- Shared ontology. William C. Wohlforth (2008) reduces all realism to three assumptions: groupism, egoism and power-centrism. Both traditions accept states as the key groups, anarchy, survival, self-help and the balance of power, and both doubt that law, trade or institutions can transform politics.
- Shared lineage. Waltz’s anarchy is Hobbes’s state of nature among sovereigns. Graham Allison‘s Thucydides Trap (Destined for War, 2017), applied to US–China rivalry, restates Thucydides on Athens and Sparta; in 2025 China’s military spending reached about $336 billion, second only to America’s.
- Waltz’s own view. In “Realist Thought and Neorealist Theory” (1990), Waltz presented neorealism as turning realist thought into theory.
- The bridge. Neoclassical realism (Gideon Rose, Fareed Zakaria, Randall L. Schweller) brings classical concerns with leaders, perception and state capacity back into a structural frame. Mearsheimer’s power-maximising states echo Morgenthau, and his How States Think (2023, with Sebastian Rosato) returns to how leaders reason through credible theories, a classical concern.
- An Indian test. Kautilya‘s mandala, in which the neighbour is the natural enemy, is classical in its advice to the king and structural in deriving enmity from position; Mohammed Ayoob‘s subaltern realism carries the tradition to post-colonial states.
Conclusion
Classical and modern realists disagree about why states compete and how to study it, not about whether they do. The continuity is a shared core of state, anarchy and power, and the debates are best read as arguments within one tradition.