The theoretical paradigm of realism emerged in the IR academy in the late 1930s to address the inadequacy of liberal idealism to understand the political currents of the inter-War period. Essentially, realism purports to explain international politics as it is, rather than how it should be; realists remain pessimistic about the prospects of peace and cooperation among nation-states in the international society. Over decades, realism has undergone a number of ideational refinements and methodological modifications, leading to several variants of the core paradigm. The two most important variants of the theory are classical realism and neorealism. The following essay shall attempt to discuss the key similarities and differences of the two approaches, and end with a comparison of these with some rival conceptions of international relations (IR).
At the onset, it is prudent to consider the core assumptions of realist theory. Only then can we proceed to individual discussions about the specific nature of the two variants under study. All strands of the realism maintain that the international system is anarchical or without any central organizing mechanism, populated by nation-states that are in permanent conflict with one another. Nation-states retain lexical priority over all other institutions and every state aims at the satisfaction of its national interests, which are defined in terms of power and capability. The ultimate goal of every state is survival.
Though classical realism emerged as a theory of international politics during the 20th century, its philosophical and theoretical heritage can be traced back to the works of thinkers like Thucydides and Machiavelli. The characterization of power politics as an inherent and fundamental aspect of human nature by Thucydides is the core foundational belief of classical realism. His account of the Peloponnesian War between Athens and Sparta remains a seminal text in the discipline, still informing scholars about the perennial pitfalls of IR. For Thucydides, international politics is a domain of an endless struggle for power, the roots of which are derived from human nature; justice, law, and society have only a little, if any, part to play. He explains the causes of the war by pointing to the unprecedented growth of the Athenian empire, and the resultant fear of the same in Sparta. The growing disparity of capabilities between the two sides was a clear and present threat to Spartan survival, necessitating an act of war to safeguard against the peril of extinction.
This introduces us to a critical concept in classical realism: the balance of power. This idea holds that “because states pursue power as a means to security, they frequently tend to expand,” and the increase of one state’s power – understood as military capability – is checked by the countervailing power of another. When one state or a group of states is threatened by the hegemonic persuasions of a powerful state, the former try to mobilize into an alliance to balance the power of the enemy.
Machiavelli and Hans J. Morgenthau offer certain qualifications to Thucydides’ ideas. The former asserts that the idea of political realism subordinates all matters of principle to the expediency of politics; power calculations and political configurations in the world are transient, and the task of states (and their leaders) is accept, accommodate, and adapt to change in international politics. The security of the state is paramount. Morgenthau, on the other hand, advanced six principles of political realism, which was to inform the making of rational foreign policy. He claimed that international politics is governed by objective laws rooted in human nature, national interests determine international policies, and these interests are objective categories which are universally valid. Morgenthau used these principles to explain the drive for power and territory during the inter-War years and the Second World War, especially the actions of Germany and Italy during 1919 to 1939.
Neorealism attempts to offer a scientific explanation of international politics, retaining a systemic persuasion which maintains that the absence of an overarching authority in international politics makes the international system anarchical, and this anarchy fuels inter-state conflict and security competition. For neorealists, anarchy offers the most comprehensive answer to the causes of war, instead of other explanations rooted in human nature or the internal configuration of states. Waltz argues that theories purport to explain laws (or law-like propositions) that identify probable or invariant associations between one or more variables and a given constant. This forms the analytical basis for his theory of neo-realism. He devises a 7-step process by which the methodological and explanatory rigor of any theory could be evaluated; theory is understood as a bounded realm or a mental picture, explaining the inter-relationship of concepts.
The lack of a central organizing mechanism or principle in the international system leads states to opt for self-help policies, since states inherently try to maximize their security and service national interests. This problem of order in IR, and the resultant effects of that order, is explained by neorealists through looking at the capability – understood as military might, economic resources, and war preparedness – of states in the international system:
…the units of the international system are functionally similar sovereign states, hence unit-level variation is irrelevant in explaining international outcomes. It is the third tier, the distribution of capabilities across units, that is…of fundamental importance to understanding crucial international outcomes.
This distribution of capabilities can then be used to obtain the number of great powers within the international system at any given point of time, and that number, determines the structure of the international system. The most stable systemic distribution for neorealists is bipolarity, as witnessed during the Cold War. Capability calculations along neorealist lines try to obtain an objective rank-ordering of state strength to provide a clearer picture of IR.
One of the principal theoretical tools of neorealism is nuclear deterrence, which explains the long bipolar peace of the Cold War by arguing that a fair number of nuclear weapons states in the international system would lead to fewer and smaller wars, while making peace in international relations more durable and stable. Power is only a means to the end of security: statesmen try to have an appropriate amount of power, but in critical situations the ultimate concern of states is survival. Therefore, states are security maximizers rather than power maximizers as classical realism claims. For Waltz, power maximization often distorts perceptions and proves dysfunctional, triggering counterbalancing coalitions of states.
A variant of neorealism called offensive realism disagrees with Waltzian structural realism on the count of how much power states crave; offensive realists argue that states tend to maximize power till they achieve hegemony, in that no “other state has the military wherewithal to put up a serious fight against it.” The anarchical structure of the international system compels states to continuously reinforce their military capabilities, since the intentions of other states are unknown; the best way to secure peace, therefore, is to amass greater power than one’s rivals. Further, neorealism argues that states may tend to balance the most potent threat, rather than balancing the greatest power, in the international system given that survival is every state’s chief aim. Threats remain a function of power – understood through geographical proximity, offensive capability and perceived intentions – but the central tendency of states is the balance of threat, rather than the balance of power as classical realism suggests.
We find, thus, that classical realism and neorealism share certain fundamental concepts of international politics, while differing in certain others. Both variants agree that the nature of the international system is anarchical, that states are the primary units of analysis and that states aim to serve their national interests. However, while classical realists locate the causes of war in human nature, neorealists do so in the anarchical structure of IR. Secondly, while classical realism contends that states are power maximizers, neorealism argues that they are security maximizers. Thirdly, classical realism believes in the balance of power, while neorealism asserts the importance of balancing threats.
Though both variants offer a compelling explanation of IR, John A. Vasquez used the Lakatosian idea of paradigmatic progress – derived from Kuhn and Popper’s ideas – to argue that realism was essentially a degenerative research program, because its many variants combined to make it unfalsifiable. Basically, Vasquez argues that any good theory should specify its limitations; disciplinary advancement can only be made once an objective standard is shown to be inadequate and a new benchmark is set. Realism escapes this process due to the variegated interpretations its proponents forward, helping to bring discrepant evidence within the theory’s fold. In fact, many have gone so far as to claim that neorealism is, at best, a pseudoscience. It has also been argued that realism fails to predict change in IR and is fundamentally a status-quoist theory; in fact, realism was guilty of failing to predict the end of the Cold War itself.
The realist response on the former count was two-fold. Firstly, it was argued that the purpose of theory was not falsification, but clarification and explanation. And secondly, it was argued that Vasquez failed to consider any meaningful sample of contemporary realist research, thus failing to grasp its potential and demonstrated progressive scholarship. To the latter challenge, it has been pointed out that the strength of realism lies not in ex-ante prediction but in ex-post explanation. Moreover, realism is not completely devoid of predictive ability, as is evident from the discouragement that the US aggression in Iraq received from eminent realists.
In the final analysis, it is prudent to compare the two variants of realism under discussion with other theories of IR, in order to show that while there may be some differences between the two, they essentially fall under the same umbrella of theoretical persuasion. Liberalism locates the causes of war in the domestic political setting; liberal internationalists contend that if internal settings are democratic, states are inherently peaceful. By extending the domestic principles to the international sphere, and the proliferation of representative systems of government within nation-states, the world can achieve a democratic peace. Neoliberalism, on the other hand, agrees partially with realism that the international structure is anarchical. However, they maintain that nation-states are not always the most important actors, and the salience of international institutions and régimes cannot be denied. Neoliberals hold an optimistic view of the world, claiming that international conflict is not inevitable, and cooperation between states remains possible if both parties can gain from such transactions. Social constructivists concern themselves with human consciousness, and argue that the normative structure of international politics shapes the identities and interests of nation-states. Social rules both regulate and constitute the actions of states, which are shaped by their underlying cultures.
Compared to the other mainstream approaches to IR, we find that classical realism and neorealism are mostly two sides of the same coin. While internal differences within the paradigm do remain, we can conclude by saying that either variant provides powerful explanations for the motives and actions of states in the international system through the ideas of self-help, statism, and survival, thereby highlighting an important analytical toolkit for the study of IR.
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