Understanding Realism in International Relations: A Comprehensive Definition

Realism remains one of the most influential and enduring theories in the study of international relations. Its principles shape the strategies of states, inform foreign policy decisions, and underpin much of the academic and strategic thinking around global power dynamics. This article explores the definition of realism, its historical foundations, key assumptions, variations within the theory, and the debates that continue to surround it today.

Defining Realism

Realism in international relations is a theoretical approach that views the international system as anarchic and dominated by states acting in pursuit of their own national interests. Central to realism is the belief that power — particularly military and economic power — is the primary currency of international politics.

According to the Oxford Reference, realism is "a school of thought in international relations theory that emphasizes the competitive and conflictual side of international relations."

Realists argue that, in the absence of a central authority (unlike domestic politics), the international sphere compels states to prioritize survival, security, and strategic interests above all else.

Historical Origins of Realism

Classical Roots

The roots of realism can be traced back to ancient political thought. Thinkers like Thucydides, in his account of the Peloponnesian War, and Niccolò Machiavelli, in The Prince, emphasized power, self-interest, and the harsh realities of political life — foundational ideas for later realist theory.

Modern Development: Post-World War Realism

Modern realism emerged in the aftermath of the two World Wars, challenging the idealistic belief that international institutions and moral diplomacy could prevent conflict. Hans Morgenthau, often regarded as the father of modern realism, articulated the theory in his seminal work Politics Among Nations (1948), emphasizing that politics is governed by objective laws rooted in human nature.

Core Assumptions of Realism

Anarchy

Realists contend that the international system lacks a supranational authority, creating a condition of anarchy. This compels states to act in ways that ensure their survival.

State-Centrism

States are the principal actors in international relations. While international organizations, NGOs, or corporations may play roles, realists argue that sovereign states hold the ultimate power.

Rational Actors

States are seen as rational entities that make decisions based on cost-benefit calculations, always aiming to maximize their security and national interest.

Self-Help

Due to the anarchic nature of the international system, states cannot rely on others for their security. Instead, they must provide for their own defense, often through arms build-ups or alliances.

Power Politics

The pursuit of power — whether to maintain, increase, or demonstrate it — is central. Military capability, economic leverage, and diplomatic influence are viewed as essential tools.

Variants of Realism

Classical Realism

Focuses on human nature as the driver of power politics. Morgenthau and others believed the lust for power is inherent in human beings.

Neorealism (Structural Realism)

Popularized by Kenneth Waltz, neorealism shifts the focus from human nature to the structure of the international system. It emphasizes how the distribution of power (unipolarity, bipolarity, multipolarity) shapes state behavior.

Offensive vs Defensive Realism

• Offensive Realists (e.g. John Mearsheimer) argue that states are inherently aggressive and seek hegemony.
• Defensive Realists believe states are security maximizers, seeking only to maintain their position and avoid unnecessary conflict.

Critiques and Contemporary Debates

Overemphasis on Conflict

Critics argue realism neglects cooperation and overemphasizes conflict. The success of institutions like the EU or the influence of international law challenges the realist assumption that anarchy leads inevitably to rivalry.

Ignoring Non-State Actors

Realism has been criticized for sidelining the role of international organizations, transnational movements, and multinational corporations, all of which shape today's global affairs.

Ethical Limitations

Realism’s focus on interest over ideology often leads to morally ambiguous or pragmatic foreign policy decisions, prompting debates about ethics and responsibility in global leadership.

Realism in the 21st Century

Despite criticisms, realism remains relevant. The return of great power rivalry (e.g. U.S.-China competition, Russian aggression in Ukraine) has renewed interest in realist perspectives. National interests, security dilemmas, and balance-of-power dynamics continue to define much of contemporary geopolitics.

Realism also influences policymaking — from deterrence doctrines and alliance strategies to arms control and economic sanctions.

Conclusion

Realism provides a powerful lens for understanding international relations by focusing on power, interest, and the structure of the international system. While it may not explain every facet of global affairs, its core tenets remain essential for analyzing state behavior, strategic rivalries, and foreign policy decisions. As the world navigates an era of multipolarity and strategic uncertainty, realism's emphasis on national interest and security is once again at the forefront of geopolitical thinking.