Realism (international relations)


Realism, in international relations theory, is a theoretical framework that views world politics as an enduring competition among self-interested states vying for power and positioning within an anarchic global system devoid of a centralized authority. It centers on states as rational primary actors navigating a system shaped by power politics, national interest, and a pursuit of security and self-preservation.
Realism involves the strategic use of military force and alliances to boost global influence while maintaining a balance of power. War is seen as inevitably inherent in the anarchic conditions of world politics. Realism also emphasizes the complex dynamics of the security dilemma, where actions taken for security reasons can unintentionally lead to tensions between states.
Unlike idealism or liberalism, realism underscores the competitive and conflictual nature of global politics. In contrast to liberalism, which champions cooperation, realism asserts that the dynamics of the international arena revolve around states actively advancing national interests and prioritizing security. While idealism leans towards cooperation and ethical considerations, realism argues that states operate in a realm devoid of inherent justice, where ethical norms may not apply.
Early popular proponents of realism included Thucydides, Machiavelli, Hobbes, and Rousseau. Carl von Clausewitz, another contributor to the realist school of thought, viewed war as an act of statecraft and gave strong emphasis on hard power. Clausewitz felt that armed conflict was inherently one-sided, where typically only one victor can emerge between two parties, with no peace.
Realism became popular again in the 1930s, during the Great Depression. At that time, it polemicized with the progressive, reformist optimism associated with liberal internationalists like U.S. President Woodrow Wilson. The 20th century brand of classical realism, exemplified by theorists such as Reinhold Niebuhr and Hans Morgenthau, has evolved into neorealism—a more scientifically oriented approach to the study of international relations developed during the latter half of the Cold War. In the 21st century, realism has experienced a resurgence, fueled by escalating tensions among world powers. Some of the most influential proponents of political realism today are John Mearsheimer and Stephen Walt.
At the 2026 World Economic Forum, Canadian Prime Minister Mark Carney's speech framed international relations through the lens of realism, outlining an approach called "values-based realism," a concept he attributed to Finnish President Alexander Stubb. Quoting Thucydides, Carney stated that "the strong do what they can, and the weak must suffer what they must," to describe what he called a "brutal reality" where the post-World War II rules-based international order no longer applied.

Overview

Realists fall into three classes based on their view of the essential causes of conflict between states:
Realism entails a spectrum of ideas, which tend to revolve around several central propositions, such as:
  1. State-centrism: states are the central actors in international politics, rather than leaders or international organizations;
  2. Anarchy: the international political system is anarchic, as there is no supranational authority to enforce rules;
  3. Rationality and/or egoism: states act in their rational self-interest within the international system; and
  4. Power: states desire power to ensure self-preservation.
Political scientists sometimes associate realism with Realpolitik,
as both deal with the pursuit, possession, and application of power. Realpolitik, however, is an older prescriptive guideline limited to policy-making, while realism is a wider theoretical and methodological paradigm which aims to describe, explain, and predict events in international relations. As an academic pursuit, realism is not necessarily tied to ideology; it does not favor any particular moral philosophy, nor does it consider ideology to be a major factor in the behavior of nations.
However, realists are generally critical of liberal foreign policy. Garrett Ward Sheldon has characterised the priorities of realists as Machiavellian and seen them as prioritising the seeking of power, although realists have also advocated the idea that powerful states concede spheres of influence to other powerful states.

Common assumptions

The four propositions of realism are as follows.
  1. State-centrism: States are the most important actors.
  2. Anarchy: The international system is anarchic.
  3. * No actor exists above states, capable of regulating their interactions; states must arrive at relations with other states on their own, rather than it being dictated to them by some higher controlling entity.
  4. * The international system exists in a state of constant antagonism.
  5. Egoism: All states within the system pursue narrow self-interests.
  6. * States tend to pursue self-interest.
  7. * Groups strive to attain as many resources as possible.
  8. Power politics: The primary concern of all states is power and security.
  9. * States build up their militaries to survive, which may lead to a security dilemma.
Realists believe that mankind is not inherently benevolent but rather self-centered and competitive. This perspective, which is shared by theorists such as Thomas Hobbes, views human nature as egocentric and conflictual unless there exist conditions under which humans may coexist. It is also disposed of the notion that an individual's intuitive nature is made up of anarchy. In regards to self-interest, these individuals are self-reliant and are motivated in seeking more power. They are also believed to be fearful. This view contrasts with the approach of liberalism to international relations.
The state emphasizes an interest in accumulating power to ensure security in an anarchic world. Power is a concept primarily thought of in terms of material resources necessary to induce harm or coerce other states. The use of power places an emphasis on coercive tactics being acceptable to either accomplish something in the national interest or avoid something inimical to the national interest. The state is the most important actor under realism. It is unitary and autonomous because it speaks and acts with one voice. The power of the state is understood in terms of its military capabilities. A key concept under realism is the international distribution of power referred to as system polarity. Polarity refers to the number of blocs of states that exert power in an international system. A multipolar system is composed of three or more blocs, a bipolar system is composed of two blocs, and a unipolar system is dominated by a single power or hegemon. Under unipolarity realism predicts that states will band together to oppose the hegemon and restore a balance of power. Although all states seek hegemony under realism as the only way to ensure their own security, other states in the system are incentivised to prevent the emergence of a hegemon through balancing.
States employ the rational model of decision making by obtaining and acting upon complete and accurate information. The state is sovereign and guided by a national interest defined in terms of power. Since the only constraint of the international system is anarchy, there is no international authority and states are left to their own devices to ensure their own security. Realists believe that sovereign states are the principal actors in the international system. International institutions, non-governmental organizations, multinational corporations, individuals and other sub-state or trans-state actors are viewed as having little independent influence. States are inherently aggressive and obsessed with security. Territorial expansion is only constrained by opposing powers. This aggressive build-up, however, leads to a security dilemma whereby increasing one's security may bring along even greater instability as an opposing power builds up its own arms in response. Thus, security becomes a zero-sum game where only relative gains can be made. Moreover, the "relative gains" notion of the realist school implies that states must fight against each other to gain benefits.
Realists believe that there are no universal principles with which all states may guide their actions. Instead, a state must always be aware of the actions of the states around it and must use a pragmatic approach to resolve problems as they arise. A lack of certainty regarding intentions prompts mistrust and competition between states.
Rather than assume that states are the central actors, some realists, such as William Wohlforth and Randall Schweller refer instead to "groups" as the key actors of interest.
Finally, states are sometimes described as "billiard balls" or "black boxes". This analogy is meant to underscore the secondary importance of internal state dynamics and decisionmaking in realist models, in stark contrast to bureaucratic or individual-level theories of international relations.

Realism in statecraft

The ideas behind George F. Kennan's work as a diplomat and diplomatic historian remain relevant to the debate over American foreign policy, which since the 19th century has been characterized by a shift from the Founding Fathers' realist school to the idealistic or Wilsonian school of international relations. In the realist tradition, security is based on the principle of a balance of power and the reliance on morality as the sole determining factor in statecraft is considered impractical. According to the Wilsonian approach, on the other hand, the spread of democracy abroad as a foreign policy is key and morals are universally valid. During the Presidency of Bill Clinton, American diplomacy reflected the Wilsonian school to such a degree that those in favor of the realist approach likened Clinton's policies to social work. Some argue that in Kennan's view of American diplomacy, based on the realist approach, such apparent moralism without regard to the realities of power and the national interest is self-defeating and may lead to the erosion of power, to America's detriment. Others argue that Kennan, a proponent of the Marshall Plan, might agree that Clinton's aid functioned strategically to secure international leverage: a diplomatic maneuver well within the bounds of political realism as described by Hedley Bull.
Realists often hold that statesmen tend towards realism whereas realism is deeply unpopular among the public. When statesmen take actions that divert from realist policies, academic realists often argue that this is due to distortions that stem from domestic politics. However, some research suggests that realist policies are actually popular among the public whereas elites are more beholden to liberal ideas. Abrahamsen suggested that realpolitik for middle powers can include supporting idealism and liberal internationalism.