Realism in International Ethics: Power Dynamics and Global Relations

When nations make foreign policy decisions, do moral principles genuinely guide their choices – or is power the real driving force? This question sits at the heart of political realism, one of the most enduring and debated frameworks in international thought. Realism does not claim that ethics are irrelevant; rather, it argues that in a world where no authority stands above sovereign states, the pursuit of power and national survival consistently overrides moral idealism. Understanding realism means grappling with an uncomfortable truth: that the international arena often operates by different rules than the moral standards we apply in everyday life.

What is political realism? 🔗

According to the Stanford Encyclopedia of Philosophy, political realism is a view of international politics that emphasizes its competitive and conflictual nature. It is usually contrasted with idealism or liberalism, which tends to highlight the potential for international cooperation. Realists hold that the principal actors in world politics are states – entities primarily concerned with their own security, driven by national interest, and engaged in a perpetual struggle for power.

What makes realism philosophically significant is its skepticism toward ethics in international affairs. National politics is the realm of authority and law, whereas international politics – realists argue – is a sphere without enforceable justice, governed instead by active or potential conflict among states where universal ethical standards have limited purchase. This does not mean realism is purely cynical; it is more accurately described as hardheaded about the limits of moral aspiration in global politics.

Realism has dominated the academic study of international relations since the end of World War II, shaping how scholars and policymakers understand conflict, alliances, and diplomacy.

Historical roots: from Thucydides to Machiavelli 🔗

Realism is not a modern invention. Its intellectual lineage stretches back to ancient Greece. In The Prince (1532), Machiavelli stressed that a leader’s primary concern is to promote national security, arguing that rulers must obey an “ethics of responsibility” – meaning they should act morally when possible, but must also be willing to use hard power when survival demands it. Machiavelli separated politics from conventional morality not to celebrate immorality, but to describe what he saw as the effective truth of governance.

Before Machiavelli, the Athenians’ famous statement during the Peloponnesian War – as recorded by Thucydides – captured the realist logic starkly: in the absence of a higher authority, the strong do what they can while the weak must accept what they must. Yet Thucydides’ realism was neither immoral nor amoral; it cautioned against both naive idealism and unrestrained cynicism – a balance that the best realist thinkers have tried to maintain.

Thomas Hobbes further developed the realist framework by characterizing the international system as a condition of permanent insecurity. His theory assumes that independent states, like individuals in a state of nature, are self-interested by default, and that without a supreme global authority to enforce rules, international relations will always tend toward competition and precarious arrangements.

Classical realism: Hans Morgenthau and the six principles 🔗

The most systematic articulation of realism for the modern era came from Hans Morgenthau, widely regarded as the father of classical realism in international relations. His landmark work, Politics Among Nations, first published in 1948, went through five editions during his lifetime and was widely adopted as a textbook in universities across the United States and Britain. Morgenthau laid out six principles of political realism that continue to frame academic debate.

The six principles in brief 🔗

The first principle holds that politics is governed by objective laws rooted in human nature – laws that are constant across time and history. The second, and most central, principle defines the national interest in terms of power: nations always define and act to secure their national interests through power, making power the master concept of political analysis. The third principle recognizes that national interest is dynamic, shifting with context and circumstance.

The fourth and fifth principles address ethics directly. Morgenthau argued that universal moral principles cannot simply be applied to the actions of states, and that nations often invoke moral principles as rhetoric to conceal what are essentially power-driven objectives. He was clear-eyed about this: nations dress up strategic calculations in the language of justice or democracy, but the underlying driver remains national interest. His fifth principle distinguishes between a nation’s moral aspirations and the universal moral law – a state’s foreign policy is not the same as a universal ethical standard, even when its leaders claim otherwise.

The sixth principle holds that power is the primary end of political action, and that the political sphere operates autonomously from economics, law, and morality. Politics, in the realist view, is a distinct domain with its own logic.

Crucially, Morgenthau was not advocating amorality. He recognized that a person who was purely “political man” would be like a beast – entirely lacking in moral restraint – while a person who was purely “moral man” would be a fool, lacking in prudence. His view was that effective statecraft requires holding both dimensions in tension.

The core logic: anarchy, self-help, and the security dilemma 🔗

What makes the realist account compelling is that it begins with a structural fact: states exist within an anarchic international system in which they are ultimately dependent on their own capabilities to further their national interests. There is no world government, no global police force, and no authority capable of enforcing agreements between sovereign nations. In such a system, states must rely on themselves – a condition sometimes called “self-help.”

This produces what is known as the security dilemma. As states build up their militaries to ensure their own survival, they may trigger fear and counter-buildup in rival states, generating arms races and heightened tensions even when no state originally intended conflict. The dilemma captures why realism sees war not as an accident or a failure of goodwill, but as an inherent possibility in an anarchic world.

In Morgenthau’s framework, every political action is directed toward keeping, increasing, or demonstrating power. Policies grounded in morality or idealism are seen as potentially dangerous, because idealistic foreign policy can lead to strategic weakness – and ultimately to a state’s domination or destruction by a more power-conscious rival.

Classical realism vs. neorealism 🔗

Morgenthau’s classical realism explained power politics through human nature – the innate drive of individuals and states to seek dominance. But in 1979, Kenneth Waltz offered a structural revision. In Theory of International Politics, Waltz modernised realism by shifting focus away from human nature to the structure of the international system itself. For Waltz, it is not that humans are inherently power-hungry; it is that the anarchic structure of the international system pushes states toward power-seeking behavior regardless of their leaders’ personal values. This is called neorealism or structural realism.

Later, John Mearsheimer pushed further with offensive realism, arguing in The Tragedy of Great Power Politics (2001) that states are not merely defensive – they actively seek to maximize relative power as the safest guarantee of survival. Mearsheimer’s framework helps explain why great powers rarely remain satisfied with the status quo.

One practical illustration: leading realists, including Morgenthau’s intellectual heirs, opposed the US invasion of Iraq in 2003, predicting that the disproportionate use of military force would generate blowback and regional instability – a prediction borne out by subsequent events.

Realism and ethics: not as opposed as it seems 🔗

A common misreading of realism is that it simply rejects ethics. The more nuanced position is that realism relocates ethics. According to the Carnegie Council for Ethics in International Affairs, ethical realism holds that power and morality are not mutually exclusive – these forces must shape and inform one another. Thinkers like Reinhold Niebuhr, whose Christian Realism complemented Morgenthau’s framework, argued that states must weigh morality alongside national interests to avoid the kind of overreach that stems from unchecked ethical arrogance.

For ethical realists in the Morgenthau-Niebuhr tradition, morality must be grounded in political reality – not discarded in its name. A state might still pursue security as its primary goal but choose methods that minimize civilian harm or respect international humanitarian law. This approach acknowledges that states operate in a competitive environment where survival is paramount, while insisting that the how of pursuing interests remains morally significant.

Realism’s critics: what it gets wrong 🔗

Despite its analytical strength, realism faces substantial criticism. Critics argue that realism’s emphasis on power and self-interest creates a self-fulfilling prophecy that can perpetuate conflict and undermine possibilities for genuine cooperation. If states assume all other states are hostile, they may act in ways that make hostility more likely – a logic that can become its own trap.

From an ethical standpoint, realism’s dismissal of universal moral principles is troubling. It risks providing intellectual cover for aggression and oppression, since virtually any harmful policy can be defended as serving the national interest. The rise of international institutions – the United Nations, the International Criminal Court, the World Trade Organization – suggests that states do, in practice, engage in forms of rule-governed cooperation that pure realism struggles to explain.

The logical validity of descriptive realism is itself questionable: the claim that states only ever pursue power is an assumption, not a proven fact, and assumptions can only be tested against evidence, not treated as self-evident truths. Liberalism and constructivism offer alternative frameworks, emphasizing the role of international norms, institutions, and shared identities in shaping state behavior – factors that pure realism tends to minimize.

Realism’s relevance today 🔗

Despite its critics, realism remains one of the most analytically useful lenses for understanding global politics. The resurgence of great power competition – between the United States, China, and Russia – looks very much like the structural dynamics realists predicted. Arms build-ups, spheres of influence, and strategic rivalries over trade and technology all reflect a realist world in which security concerns consistently overshadow moral rhetoric.

At the same time, even leading statesmen now acknowledge that pure power politics has limits. At the 2026 World Economic Forum, Canadian Prime Minister Mark Carney’s speech framed international relations through the lens of what he called “values-based realism” – an acknowledgment that the post-WWII rules-based order is under strain, but that values cannot simply be abandoned without cost. This kind of synthesis – taking power seriously without discarding ethics – is precisely the middle ground that ethical realists like Morgenthau always advocated, even if it is rarely credited to him.

The tension between power and principle is not a problem that international relations theory has solved – or ever will. Realism reminds us that idealism without power is futile, while the ethical tradition reminds us that power without moral direction is dangerous. As the Stanford Encyclopedia of Philosophy puts it, it is utopian to ignore the reality of power in international relations, but equally blind to rely on power alone.

What do you think? If states are structurally compelled to prioritize survival over ethics, can international institutions ever provide a genuine moral framework for global behavior – or are they simply tools that powerful states use to legitimize their interests? And is there a meaningful difference between a foreign policy driven by ethical conviction and one driven by national interest dressed in moral language?

References

1. https://plato.stanford.edu/entries/realism-intl-relations/
2. https://www.britannica.com/topic/realism-political-and-social-science
3. https://www.e-ir.info/2018/02/27/introducing-realism-in-international-relations-theory/
4. https://plato.stanford.edu/archives/sum2017/entries/realism-intl-relations/
5. https://en.wikipedia.org/wiki/Hans_Morgenthau
6. https://politicalscienceblog.com/morgenthau-six-principles-of-realism/
7. https://yoopery.com/morgenthau-six-principles-of-realism/
8. https://iep.utm.edu/polreal/
9. https://en.wikipedia.org/wiki/Realism_(international_relations)
10. https://carnegiecouncil.org/explore-engage/key-terms/ethical-realism