Introduction
This essay explores the explanatory power of realism, a foundational theory in international relations (IR). Realism posits that states are the primary actors in an anarchic international system, driven by self-interest and the pursuit of power to ensure survival. The purpose of this essay is to assess how effectively realism explains state behaviour, international conflict, and cooperation. It will examine realism’s core assumptions, evaluate its strengths in explaining historical and contemporary events, and address its limitations in accounting for non-state actors and ideological motivations. By critically engaging with key arguments, this essay seeks to provide a balanced understanding of realism’s relevance for undergraduate students of IR.
Core Assumptions of Realism
Realism, rooted in the works of thinkers like Hans Morgenthau, is built on several key assumptions. First, it views the international system as anarchic, lacking a central authority to enforce rules (Morgenthau, 1948). States, as rational actors, prioritise national interest—often defined as security and power—above moral or ideological concerns. Secondly, realism assumes that human nature is inherently self-interested, a perspective that translates into state behaviour (Waltz, 1979). These assumptions provide a framework for understanding why states engage in power struggles, form alliances, or pursue military capabilities. For instance, the Cold War rivalry between the United States and the Soviet Union can be explained through realism as a competition for dominance in an anarchic system, with each state seeking to counterbalance the other’s power.
Strengths in Explaining Conflict and State Behaviour
One of realism’s primary strengths lies in its ability to explain conflict and security dilemmas. The theory offers a compelling lens for analysing historical events such as the two World Wars, where states’ pursuit of power and territory led to large-scale conflict. Furthermore, realism’s focus on balance of power remains relevant in contemporary IR. For example, China’s military expansion in the South China Sea can be interpreted as an attempt to assert regional dominance, prompting responses from the United States and its allies to maintain equilibrium. As Waltz (1979) argues, states inherently seek to balance against perceived threats, a dynamic that realism captures effectively. This predictive capacity demonstrates realism’s explanatory power in straightforward, state-centric scenarios.
Limitations and Criticisms
However, realism is not without limitations. It struggles to account for the role of non-state actors, such as international organisations or terrorist groups, which have become increasingly significant in global politics. For instance, the influence of the United Nations in peacekeeping or the impact of groups like ISIS on state security cannot be fully explained through a realist lens, as it prioritises state sovereignty over other entities. Additionally, realism often overlooks ideological and cultural factors. The Arab Spring, driven by domestic demands for democracy rather than state power, challenges realism’s assumptions about rational, unitary state behaviour (Baylis et al., 2020). These gaps suggest that while realism provides a robust framework for understanding power dynamics, it is less equipped to address complex, multi-dimensional issues.
Conclusion
In conclusion, realism offers significant explanatory power in international relations by highlighting the centrality of power, anarchy, and state interest in shaping global politics. Its ability to elucidate conflict and balance-of-power dynamics, as seen in historical and contemporary cases, underscores its enduring relevance. Nevertheless, its state-centric focus and neglect of ideological or non-state influences limit its applicability in a globalised world. For students of IR, realism remains a vital starting point for analysis, though it should be complemented by other theories to capture the full complexity of international affairs. Indeed, understanding its strengths and weaknesses enables a more nuanced approach to studying global interactions.
References
- Baylis, J., Smith, S., and Owens, P. (2020) The Globalization of World Politics: An Introduction to International Relations. 8th ed. Oxford University Press.
- Morgenthau, H. J. (1948) Politics Among Nations: The Struggle for Power and Peace. Knopf.
- Waltz, K. N. (1979) Theory of International Politics. Addison-Wesley.

