Balance of Power

The concept of balance of power in international relations is a fundamental theoretical framework developed to explain the distribution of relative power among states and its impact on the stability of the international system. The concept has been used both descriptively and normatively to analyze states’ efforts to secure their security, preserve their sovereignty, and sustain the international order. Historically, from the Westphalian system in Europe to the bipolar structure of the Cold War, the balance of power has been a central principle shaping the nature of both war and peace. States have adapted their behavior according to the distribution of power in the system; when one state gained excessive power, others adopted balancing policies, making this a fundamental systemic reflex. Within this framework, the balance of power has been regarded as a “balancing mechanism” that prevents the collapse of the international order. However, in the complex geopolitical structure of the 21st century, factors beyond military or economic power—such as technology, diplomacy, information flows, and soft power—have become decisive components of this balance. Thus, the balance of power is not a static concept historically; it is a systemic logic that transforms according to the political, economic, and technological conditions of each era.

Theoretical Foundations

The intellectual foundation of balance of power theory rests on the anarchic nature of the international system and states’ existential pursuit of security. This approach, central to realism, argues that in the absence of a central authority in international relations, states must accumulate power to ensure their own security. Classical realism has an intellectual tradition stretching from Thucydides’ History of the Peloponnesian War through Machiavelli’s The Prince to Hans Morgenthau’s Politics Among Nations. In this view, power is not merely a tool but a fundamental element that defines the nature of international politics. According to Morgenthau, states are inherently driven by the pursuit of power; therefore, the international system is characterized by a continuous cycle of competition, balancing, and counterbalancing. In this classical version of the balance of power, stability is possible only when no state can subjugate the others.

Structural realism, or neorealism, introduced by Kenneth Waltz in his 1979 work Theory of International Politics, provided a systemic explanation of the balance of power. According to Waltz, the primary determinant of state behavior is not human nature but the anarchic structure of the system. Under the constraints of this structure, states act according to the principle of “self-help,” as there is no central authority to guarantee their security. In this context, power becomes a relative concept: a state’s power only gains meaning when compared to the power of other states. This logic is used to explain the forms of polarity in the system—unipolar, bipolar, multipolar—and the stability levels associated with each. This variant of realism treats balance not as a policy but as a systemic necessity. In contrast, neoliberal theories argue that international cooperation institutions can replace balance, while constructivist approaches define power not merely as material but also as ideational. Constructivists such as Alexander Wendt argue that power is constructed through social relations and shared identities, and therefore balance is shaped by perceptions and norms. Thus, the balance of power is reinterpreted as a process constructed not only through armaments and military alliances but also through identities, legitimacy, and normative acceptances.

Historical Development

The historical origins of the balance of power concept extend back to the 1648 Treaty of Westphalia, which symbolized the birth of the modern state system. The Westphalian order established a horizontal rather than hierarchical structure in international relations by recognizing state sovereignty. Maintaining this system required the balance of power among states. In the 18th century, balance of power policies in Europe became particularly evident through Britain’s role as the “balancing power.” Britain aimed to preserve the continental balance by supporting weaker states to prevent any single power from dominating the European continent. This understanding was institutionalized after the Napoleonic Wars at the 1815 Congress of Vienna; the “Concert of Europe” system preserved continental stability for nearly a century through collective diplomacy among the great powers. However, in the early 20th century, industrialization, colonial competition, and nationalism hardened alliance systems and laid the groundwork for the First World War. During this period, the function of the balance of power did not prevent war but rather intensified bloc formation and mutual distrust.

The post-Second World War era gave rise to a different form of balance of power: bipolarity. The ideological and military rivalry between the United States and the Soviet Union divided the global system into two opposing blocs. During this period, nuclear deterrence emerged as a new instrument of the balance of power, creating an environment of “cold peace” instead of direct war. Yet this balance was fragile: even a minor crisis, such as the Cuban Missile Crisis, carried the risk of escalating into global conflict. With the dissolution of the Soviet Union in 1991, the system became unipolar; the United States rose to a position of global hegemony through its military, economic, and cultural power. Nevertheless, in the 21st century, the rise of China, Russia’s resurgence, and the growing influence of “middle powers” such as India, Brazil, and Türkiye have pushed the international system back toward multipolarity. Thus, the balance of power remains a valid concept for explaining the dynamic nature of the international system, as it did in the modern era.

Balance of Power Mechanisms

In practice, the balance of power operates through both internal and external mechanisms. Internal balancing refers to a state enhancing its own economic and military capacity to ensure its security. This can be achieved through developing defense industries, arms buildups, or increasing technological superiority. External balancing, by contrast, involves states forming alliances to act collectively against common threats. Throughout history, these two methods have complemented each other. For example, the formation of NATO and the Warsaw Pact during the Cold War are among the most prominent examples of external balancing. However, in the contemporary era, these mechanisms are no longer limited to military tools. Economic sanctions, diplomatic pressure, voting blocs in international organizations, and technological cooperation networks have become integral components of modern balancing strategies.

In the new era, the concept of balancing has expanded further. The approach of “soft balancing” refers to states limiting the power projection of rivals not through direct military opposition but through diplomatic, economic, or institutional means. For instance, the United States’ creation of multilateral alliances such as QUAD and AUKUS to constrain China’s influence in the Asia-Pacific region is a concrete example of soft balancing. Conversely, the concept of “asymmetric balancing” describes the efforts of weaker actors—such as regional powers or non-state actors—to counter great powers through cyberattacks, disinformation, or economic resistance strategies. Thus, the contemporary understanding of the balance of power has become a multidimensional system that operates not only through tanks, armies, and alliances but also through technology, information, and international institutions.

Balance of Power in the Contemporary Era

In the 21st century, the balance of power has taken on a far more complex form than the simple polarity models predicted by classical realism. According to Jennifer Lind’s 2024 analysis, the global order is evolving back toward a bipolar structure; the competition between the United States and China has extended beyond military rivalry into economic, technological, and normative domains. China’s growing position in global supply chains, along with its investments in quantum technology and artificial intelligence, is generating “systemic capacity” beyond classical military power. This situation is constraining the United States’ traditional hegemonic advantage and compelling it into a more complex arrangement of “burden sharing” with its allies. At the same time, actors such as the European Union, Japan, and India have created layered power distributions by establishing regional balances outside the two-pole system. Thus, the international system is moving toward a multidimensional and flexible structure that cannot be managed from a single center.

The work of Sandra Ejituwu and Ngozi Obi demonstrates that in the contemporary system, the concept of balance is intertwined not only with military deterrence but also with economic dependencies, energy transition policies, and global governance mechanisms. Due to globalization, interstate relations have moved beyond zero-sum dynamics and transformed into a model of “competition within interdependence.” Therefore, today’s balance of power is a composite of armed force, economic stability, energy security, technological superiority, and diplomatic influence networks.

Critiques and Contemporary Debates

In modern literature, the balance of power theory has been critiqued from multiple angles. Daniel Nexon argues that the classical logic of balance no longer operates fully in today’s international system because the influence of non-state actors and global institutions has grown. Nevertheless, he contends that the theory is not entirely obsolete but requires redefinition. According to Nexon, balancing is now conducted not only through military alliances but also through information systems, economic networks, and international legal mechanisms. On the other hand, hegemonic stability theory posits that international order depends not on the balance of power but on the institutional stability provided by a dominant power (hegemon). In contrast, power transition theory argues that the rise and decline of great powers increase the risk of systemic conflict. These two approaches are viewed not as replacements for balance of power theory but as complementary explanatory frameworks.

The balance of power continues to exist in international relations as both an explanatory and a normative concept. Throughout history, it has played a central role in understanding states’ security pursuits, alliance policies, and cycles of war and peace. However, in the modern era, the balance of power is no longer measured solely by the size of armies or nuclear capacity. Today’s understanding of balance encompasses the sum of economic productivity, technological innovation capacity, diplomatic influence, and normative legitimacy. Therefore, in the 21st century, the balance of power has become not merely a mechanism for preventing war but a dynamic stability strategy essential for the sustainability of global governance. As the international system is reshaped by new power elements such as technological transformation, climate change, energy security, and the information economy, the principle of the balance of power retains its role as the most fundamental regulatory mechanism among these variables.