The foremost principle of International Relations (IR), realism provides a convincing explanation for the universal state of war between states. Despite some commonality of a shared nucleus of assumptions and ideas between classical realism and neo (or structural) realism, classical realism is more closely linked with the basis of thought professed by Thucydides, Machiavelli, and Morgenthau. This conviction is that the drive for power and the will to dominate is a fundamental aspect of human nature that is transferred to the arena of IR and states’ interaction with other states. This driving force is considered an extension of the ego, thus provides essential continuity for the power-seeking behavior of states. Simply stated in realist phraseology, man is neither benevolent nor kind, but rather is self-centered, competitive and has a voracious appetite.
Despite its domestic system being ordered and hierarchical, the realistic international system has no hierarchy and is anarchic because there is no higher authority than the state with the constant turmoil between states because of the lack of some higher controlling governmental entity. Therefore, sovereignty is foremost and each state is considered “an equal” in the international system with their individual influence directly related to their potency in relation to their fellow IR actors. Of course, with that said, from the Realist viewpoint, states are the primary actors with non-governmental agencies in a much smaller dependent role on the IR stage.
Thucydides, the historian of the Peloponnesian War maintained that the primary goal of all states is survival and thus the conflict between Sparta and Athens was inevitable as both states vied for expansion. In their move towards state survival, they amass resources in order to improve their national security and invariably fall into the security dilemma as each state attempts to establish them in a stronger position than that of their counterparts. As shown in the Melian dialogue ( “The strong do what they have the power to do and the weak accept what they have to accept.” Niccoló Machiavelli agreed with Thucydides’ premise that power of the state was related to the aggressive and opportunistic propensities of humankind. Machiavelli took it a step further by declaring that all obligations and treaties with other states must be disregarded if the security of the community is under threat and that expansion is legitimate in order to gain more security. In his book, The Prince, Machiavelli advocated that the prince is skillful at subordinating principles to policies and that he should be prepared to adapt to the ever-changing power-political configurations of world politics. It is classical realism to believe that it is the nature of man that competition, fear, and war can be explained.
Morgenthau, although a classical realist agreed with other modern proponents of classical realism who believed that the inherent anarchy of International Relations could be alleviated by “wise leadership and the pursuit of the national interests that were more compatible with International Order.” This interpretation of realism attempts to modify the inherent anarchy with a possibility of more peaceful reconciliation between states accomplished by statesmanship as opposed to sheer force of will.
Structural realism (neorealism)
Kenneth N. Waltz’s interpretation of neorealism veers from classical realism and seems to fit the reality of the modern international stage by incorporation of a more structured evaluation of anarchy by establishing all states as sovereign within the limits of their capabilities. Central to sovereignty, is the desire by all states for survival and to increase their relative power. Of course, the uncertainty of the international relationships increases distrust between states also known as the security dilemma. According to Waltz, this structural system consists of three integral elements – organizing principle, differentiation of units and distribution of capabilities. Waltz also explains further that there are two organizing principles of structural realism: the anarchy of the international system and the hierarchy of the domestic, which is of course the basis for domestic order.
Incumbent upon structural realism is the rank-ordering of Great Powers which is necessary to determine the structure of the international system. The two post-WWII powers, the United States and the USSR were the sum of the bipolar international system. This system was not considered as stable as the pre-WWII system with 4-5 Great Powers, was considered a far more stable arrangement. However, according to Waltz that rather than power, sensible statesmen look for security due to the potential for response by other states in a coalition that join forces to respond to a state’s power.