Realism is commonly perceived as the “orthodoxy” of international relations. Realism emerged as a critique of inter-war idealism and came to full prominence after the outbreak of World War Two and the failure of Wilsonian principles. The theory is based upon the works of philosophers such as Thucydides, Machiavelli and Hobbes. The traditional definition of realism lies within the Melian dialogue of Thucydides ‘History of the Peloponnesian War’ when it is stated that the strong do what they have the power to do and the weak accept what they have to accept.”. It is a broadchurch theory and therefore cannot be monolithic, it is comprised of a number of realisms. The varieties are diverse, but they remain more similar than they are different. Realisms can be classified by time period, and this is argued to be the “most simple distinction”, they can be organised into three periods, classical, modern and contemporary. The main strands of realism are classical realism, demonstrated by theorists such as Morgenthau and Carr, and structural (neo) realism, developed by Waltz and Mearsheimer. More recently, other, more modern, strands of the theory such as neoclassical realism have been developed to counteract critiques of the study. In context, neoclassical realism is more current and flexible in its approach, making it more relevant, but classical realism is more closely in line with realism’s conventional definition.
All of the varieties of realism share key principles and assumptions, and their similarities vastly outweigh their differences, as is well portrayed by Donnelly who states it is “dangerous to overemphasize the differences”. Donnelly’s approach to the varieties of realism is convincing as all realisms are based upon the same founding principles and grouped within the same school of thought. All realists adopt a pessimistic view of the world system and are largely reactionary in their approach. The core assumptions of realism, shared by all varieties, are statism, survival and self-help. These principles underpin all conclusions within realism and cause all realists to place paramount importance upon the concept of power and military capability to enable state survival. The state is seen as the main actor, and it is the duty of the state to ensure continuity and security in an anarchical international order. Key similarities can be seen within the works of the leading theorists. For example, Morgenthau well defines classical realism’s approach to international relations by stating his 6 principles of political realism, including notions such as the “concept of interest defined in terms of power”, suggesting power to be the goal and a belief that power is necessary to ensure survival as power determines outcomes. This has much in common with structural realism, for example the notion presented by Waltz that a state’s “incentive is to put itself in a position to be able to take care of itself since no one else can be counted upon to do so”, has highly similar connotations. Waltz therefore argues the same point. Furthermore, varieties of realism can be argued to be similar as the theory as a whole fell under scrutiny following the collapse of the Soviet Union in 1991, and the peace that ensued. The end of the cold war signalled a move towards peace and interdependence which allowed for the rise of liberalism. Both classical and structural realism failed to account for peace and were heavily criticised for their approach, it was a “key blow”, (neoclassical realism is exempt as it was not developed until after the cold war). The criticism that realism faced evidences similarities between the varieties as classical and structural realism were subject to the same denunciation. However, A notion could be presented to suggest that the variants of realism are only similar due to the vast differences between them and other schools of thought such as liberalism or the English School. However, this cannot be the case as the realisms are based upon the same principles and all realists adopt the same method of protectionist thinking.
However, there are differences between the varieties of realism, hence their distinction within the theory, but these differences are not significant enough to suggest the varieties should not remain under a single broad theoretical heading. Despite this, the differences among the varieties do exist and they are well evidenced, for example, Stephen Brooks argues of “duelling realisms”. The key difference between the varieties of realism is the reasoning behind the desire for power by the states and the reasoning behind outcomes. Classical realists believe human nature to be the cause of all outcomes in international politics due to “insatiable human appetites” which desire power and gain. The notion stems from Hobbes’ idea of a state of nature, whereby human nature rules due to lack of constraint, as is the case in the international system of anarchy, which has been described by John Vincent as “grim and insoluble”. The lack of authority, in the eyes of classical realists, allows for the worst aspects of human nature to be displayed, “altruism is an illusion”, states act in a self-seeking manner due to inherent human values. Contrasting to this, structural realists believe the international system of anarchy causes insecurity and a need for measures of protection. Therefore, through fear the anarchical system causes the desire for power, not human nature. For example, Waltz emphasises this point by stating that structural realism studies “how the structure of the system, and variations in it, affect the interacting units”. Classical realism therefore looks at outcomes and possibilities from the perspective of the state, a bottom up view, and structural realism takes the perspective of the system, a top down view. In addition, neoclassical realism looks at unit-level issues and focuses upon choices made by states and the role of leadership in understanding outcomes in international politics, this makes neoclassical realism the most flexible approach as it allows for uncharacteristic behaviour outside of the norms of human nature and does not constrain all states as having to make the same choices due to the system they operate within. Nonetheless, the varieties of realism remain more similar than different as their differences are all seeking to explain the same issue, the desire for power, the differences relate back to the core assumptions.
The differences between the realisms cause the extent of relevance to the traditional definition of realism to vary.
Furthermore, there is debate over which is the variety of the theory most applicable to the international situation. The most appropriate theory is neoclassical realism. The relevance of realism was questioned in the post-cold war era as within the theory notions of cooperation were not taken into account. Consequently, the rise of a liberal international order (liberal internationalism 2.0) was not in line with the policies of both classical and structural realism. However, neoclassical realism, which was developed after the Cold War (Rose 1998), presents a more convincing argument in the contemporary situation.
Trump and classical realism.