Core Assumptions of Realism in International Relations

International relations is fundamentally shaped by competing theories that attempt to explain how nations interact on the global stage. Among these frameworks, Realism stands as one of the oldest and most influential perspectives. At its core, Realism is built upon several key assumptions about the nature of international politics that profoundly influence how states behave toward one another. These foundational beliefs provide a lens through which many political leaders and theorists understand global affairs, emphasizing power dynamics, security concerns, and national interests above all else.

The state as the primary actor in international relations 🔗

The first and perhaps most fundamental assumption of Realism is that sovereign states are the principal actors in international politics. This state-centric approach distinguishes Realism from other theoretical frameworks that might emphasize the role of international organizations, multinational corporations, or non-governmental organizations.

According to realists, despite the proliferation of transnational actors in the modern era, states remain the only entities with:

• Legitimate authority: States possess the exclusive right to make and enforce laws within their territories
• Sovereignty: They maintain ultimate decision-making power over their domestic and foreign policies
• Monopoly on force: States control the legitimate use of violence both internally and in relations with other states

This focus on states as unitary actors means that realists typically analyze international relations by examining state behaviors, motivations, and interactions rather than those of individual leaders or international bodies. While acknowledging that domestic politics and leadership personalities can influence foreign policy, realists maintain that external constraints and opportunities in the international system ultimately drive state behavior.

The “black box” view of states 🔗

Classical realists often treat states as “black boxes” or unified entities with coherent national interests. This simplification allows them to focus on interstate dynamics without getting bogged down in the complexities of domestic politics. However, this approach has been criticized for overlooking how internal factors-regime type, leadership psychology, or domestic political pressures-can significantly impact foreign policy decisions.

Nevertheless, even contemporary realists who acknowledge the importance of domestic variables maintain that external pressures from the international system tend to push states toward similar behaviors regardless of their internal composition.

The anarchic nature of the international system 🔗

Perhaps the most distinctive assumption of Realism is that the international system exists in a state of anarchy. By “anarchy,” realists don’t mean chaos or disorder but rather the absence of a legitimate central authority above states that can enforce rules, resolve disputes, or protect states from one another.

Unlike domestic political systems where governments maintain order and enforce laws, the international arena lacks any overarching authority with the legitimate power to control state behavior. The United Nations, international courts, and other global institutions exist, but they lack independent enforcement capabilities and ultimately depend on state consent and cooperation.

Implications of anarchy 🔗

This anarchic condition has several profound implications for international relations:

• Self-help system: States must ultimately rely on themselves for protection and advancement of interests
• Security dilemma: Actions taken by one state to increase its security often make other states feel less secure, potentially triggering arms races or conflicts
• Uncertainty about intentions: States can never be entirely sure about the current or future intentions of other states
• Limited cooperation: Meaningful cooperation is difficult to achieve and maintain when states fear exploitation or abandonment

From this perspective, international politics resembles what philosophers have called a “state of nature”-a condition where, lacking external constraints, actors must provide for their own security and welfare. This anarchic environment creates persistent insecurity that shapes how states perceive and interact with one another.

The primacy of power and security 🔗

Given the anarchic environment and the resultant self-help nature of the international system, realists argue that states must prioritize their own security and power accumulation. Security becomes the paramount concern because, without it, a state cannot ensure its survival or pursue any other goals.

For realists, power is the currency of international politics. They define power primarily in material terms-military capabilities, economic resources, population size, territory, and technological advancement. These tangible assets determine a state’s ability to defend itself and influence others.

The balance of power 🔗

The distribution of power among states creates what realists call the “balance of power”-a central concept in realist theory. States are highly sensitive to changes in this balance and often take actions to prevent any single state from becoming too powerful. This can lead to:

• Internal balancing: States building up their own military and economic capabilities
• External balancing: States forming alliances to counter potential hegemons
• Bandwagoning: Weaker states aligning with, rather than against, the dominant power

Realists see the balance of power not as an unfortunate reality but as a necessary mechanism for maintaining stability in an anarchic system. When power is relatively balanced among major states, the likelihood of large-scale conflict may decrease as potential aggressors are deterred by the costs and risks of war.

Rationality and the pursuit of national interest 🔗

Realists assume that states are rational actors that calculate costs and benefits when making foreign policy decisions. This doesn’t mean states never make mistakes or that emotions never influence decision-making. Rather, realists argue that the competitive nature of international politics punishes irrational behavior and creates strong incentives for states to act in their self-interest.

The concept of “national interest” is central to realist thinking. While this term can be interpreted in various ways, realists typically define it in terms of security, power, and survival. Other goals-promoting democracy, defending human rights, or spreading particular ideologies-are secondary concerns that states can pursue only after securing their primary interests.

Power as both means and end 🔗

For realists, power serves as both a means to achieve security and other goals and sometimes as an end in itself. Classical realists like Hans Morgenthau argued that states have an inherent will to power rooted in human nature. In contrast, structural realists or neorealists like Kenneth Waltz emphasize that states seek power primarily as a means to ensure security in an anarchic system.

This focus on power and interest leads realists to be skeptical of idealistic approaches to international relations that emphasize international law, morality, or universal values. While not denying the existence of ethical considerations in foreign policy, realists maintain that prudence and pragmatism must guide state actions in a competitive international environment.

The importance of material resources 🔗

Realists place special emphasis on material capabilities as the foundation of state power. These tangible resources include:

• Military assets: Size and quality of armed forces, weapons systems, and strategic capabilities
• Economic strength: GDP, industrial capacity, natural resources, and technological advancement
• Geography: Territory size, access to seas, natural barriers, and strategic location
• Population: Size, education level, and cohesion of the citizenry

These material factors determine a state’s ability to project power, deter potential aggressors, and influence international outcomes. While realists acknowledge that non-material factors like diplomatic skill, national morale, or government efficiency can enhance how effectively material resources are used, they view tangible capabilities as the bedrock of power in international relations.

The security of material resources 🔗

Beyond simply possessing material resources, realists emphasize the importance of securing reliable access to these resources. This helps explain why states often compete for control of strategic territories, sea lanes, or natural resources like oil and rare minerals. The drive to secure these resources can be a significant source of international conflict when states perceive resource scarcity or vulnerability in their supply chains.

The pessimistic view of human nature 🔗

Classical realists, in particular, ground their theory in a relatively pessimistic view of human nature. Drawing on thinkers like Thucydides, Machiavelli, and Hobbes, they argue that humans-and by extension, states-are inherently self-interested, power-seeking, and competitive.

This assumption about human nature helps explain why realists believe that international conflict is recurring and inevitable. Even when states cooperate, realists see this cooperation as fragile and contingent on calculations of self-interest rather than shared values or ideals.

The tragedy of great power politics 🔗

John Mearsheimer, a prominent contemporary realist, describes international politics as a “tragedy” because conflict emerges not necessarily from evil intentions but from the security requirements of states in an anarchic system. Even states that merely wish to ensure their own security may take actions that threaten others, leading to recurring security dilemmas and potential conflicts.

This pessimistic outlook leads realists to prioritize prudence, moderation, and the careful management of power relations over transformative or idealistic goals in foreign policy. For realists, the best that can be achieved is not a harmonious world order but a stable balance of power that minimizes the risk of catastrophic conflicts.

Implications for international cooperation and institutions 🔗

Given their assumptions about anarchy, power, and state interests, realists are generally skeptical about the potential for robust international cooperation and the effectiveness of international institutions. They view institutions like the United Nations not as independent actors but as instruments created by powerful states to advance their interests.

According to realists, international agreements and organizations:

• Reflect power relations: They tend to mirror existing power distributions rather than transform them
• Lack independent authority: They cannot enforce compliance without the backing of powerful states
• Remain contingent: States will abandon them when they no longer serve national interests

This doesn’t mean realists see no value in international institutions. Rather, they view them as limited tools that can help states coordinate policies, reduce transaction costs, and manage conflicts under certain conditions. However, realists maintain that states will never surrender true sovereignty to international bodies when core security interests are at stake.

Contemporary relevance of realist assumptions 🔗

Despite challenges from liberal institutionalism, constructivism, and other theoretical approaches, realism’s core assumptions continue to provide powerful explanatory tools for understanding many aspects of international relations today. The persistence of security competition among major powers, the limitations of international institutions in resolving core conflicts, and the continued centrality of states in global politics all suggest the enduring relevance of realist insights.

Events like Russia’s annexation of Crimea, China’s assertiveness in the South China Sea, and the competitive dynamics of nuclear proliferation are often analyzed through realist frameworks. Even as globalization and transnational challenges like climate change create incentives for cooperation, realist assumptions help explain why such cooperation remains difficult to achieve and sustain, particularly on issues touching on national security.

The COVID-19 pandemic provided another illustration of realist dynamics, as states competed for scarce medical supplies and vaccines while international institutions struggled to coordinate an effective global response. Such episodes reinforce realism’s emphasis on the primacy of state interests and the fragility of international cooperation under pressure.

Critical perspectives on realist assumptions 🔗

While realism offers powerful insights, its core assumptions have faced significant criticisms:

• Overemphasis on conflict: Critics argue that realism underestimates the potential for genuine cooperation among states
• Neglect of domestic politics: By treating states as “black boxes,” realism may miss how internal factors shape foreign policy
• Material bias: The focus on material capabilities may undervalue the importance of ideas, norms, and identities in international relations
• State-centrism: In an age of globalization, non-state actors play increasingly significant roles that realism may not adequately address

These critiques have led to refinements within realist theory itself, including neoclassical realism’s incorporation of domestic variables and defensive realism’s more nuanced view of how states pursue security. They have also contributed to the development of alternative theoretical approaches that emphasize different aspects of international politics.

What do you think? Does the realist emphasis on power and security still provide the most useful framework for understanding international relations in today’s interconnected world? How might climate change, pandemics, and other transnational challenges alter the applicability of traditional realist assumptions about state behavior and the international system?