“Right, as the world goes, is only in question between equals of power, where the strong do what they can and the weak suffer what they must”To understand forms of realism and its heavy criticisms, one needs to understand its philosophical origins and thus, this quote by Thucydides predating BCE accurately portrays the attitude that most realists have. Realists are the first to “attempt to explain, model, and prescribe political relations” by stressing the key factor of power in the global scale and within the domestic arena, the anarchical and active conflict among states and highlights that security is the central problem in international relations as well as a competitive endeavour. These principles highlight the lack of use of ethical norms. Thus, this conveys one of the criticisms of the ideology. Nonetheless, not all realists believe in a lack of ethics. This is then the differentiation between Classical Realism and Neorealism. Thus, in this essay, I will explore the differences in characteristics between the different forms of realism and highlight why these have been heavily criticised throughout history.Theorists such Hans Morgenthau characterised what was to be known as classical liberalism by highlighting 6 key principles in his book, ‘Politics Among Nations’. He states that realism is based on “objective laws that have their roots in unchanging human nature”. Thus, the laws of politics are permanent and unchanging as these are inherited in human nature. The second principle being about the centrality of power and highlights how ‘the concept of interest defined in terms of power’ plays an autonomous role in politics rather than other spheres such as economics and ethics. Furthermore, through this assumption, realism takes actions in the past, present and retraces them for the future. Third principle being the concept that self-interest is a basic fact of the human condition which “each and every man either more or less” has. However, he highlights with the instability of international society, a “balance of power” is an instrument that is capable of operating in the political arena. Morgenthau’s fourth principle focuses on ethics of international relations being different to private morality. Thus, Morgenthau highlights how universal principles cannot be applied to the action of states in their abstract universal formulation, but …they must be filtered through the concrete circumstances of time and place.” This principle is conveyed in Nehru’s statement where he claims, “who will live, if India dies” and thus highlights how statesmen have heavier responsibility than an individual Thus, caution should guide political action. This then leads on to the next principle. Morgenthau places an emphasis on the idea that all state actors must be looked as solely political entities pursuing their interests. Following this, justice can be done to all of them and be able to pursue policies that respect the interests of other nations while also protecting their own. Lastly, Morgenthau argues that policies must arise out of political analysis. He argues that policy needs to be guided by political considerations; not follow legal and moral guidelines as it has previously done. As a result, the power of a country and the welfare of its citizens have been undermined. Lastly, he highlights how political realists maintain the autonomy of the political sphere as the economist, the lawyer, the moralist theirs. Thus, each think in terms of interest as defined by what they believe in. Thus, a political realist would ask, “How does this policy affect the power the nation?” The last principle incites heavy criticism, but why? Well, Robert Kaufman analyses the pessimism within Morgenthau’s work and why it lays elements of bias. “Morgenthau, like many many German academics escaping from Hitler’s Germany, retained a somberpessimism more emblematic of German thought than the greater optimismof the American realist tradition” and thus his pessimistic outlook roots back from his readings on St Augustine’s “the inevitability and the evilness of man’s lust for power”. This conveys how he looked at things from a one dimensional perspective. Morgenthau argued that “human nature itself, rather than institutions, was responsible for the misuse of power and its temptations”. Further proving that his assessment of man’s predicament in the political arena has elements of bias information due to his upbringing in totalitarian Germany.Further analysation of Morgenthau’s principles highlight how classical realists wrote with the “desire to reach a wider audience” and focused on a “wide range of material”. Thus, when the 1950s and the 1960s came around, his outlook that the nation-state was a key, unitary actor in world politics was becoming an outdated where new international actors were becoming more prominent figures such as multinational corporations and non-governmental organisations. Furthermore, as Morgenthau highlights in his book, military power was a seen as a central part of classical realism. However, this was not proved, especially in US foreign policy and was prevalent in the Vietnam War where military power was not effective.Neorealism differs significantly. Neorealism, or structural realism, is normally associated with Defensive scholar Kenneth Waltz and his book, ‘Theory of International Relations’ where he departs focus from human nature and puts attention on how the structural constraints affect state behaviour and interaction in the international system. The principles in this ideology which differentiate from other philosophies centre around the organising principle of the international system – anarchy (Waltz 1979, p.89). The characteristics such as ‘anarchy’ and ‘structure’ are intertwined. The structure of the international system is anarchical, thus, there is an absence of a world government. “It simply means that there is no centralized authority, no night watchman or ultimate arbiter, that stands above states and protects them.” (Mearsheimer, 2001) The inexistence of a global authority highlights a self-help system where independence and responsibility of one’s state is crucial as there is no 999 number to call. Thus, defensive realists such as Waltz believed that it would be “unwise for states to try and “maximise their share of world power, because the system will punish them if they attempt to gain too much power”. Contrasting to this, there is also another variation of neorealism. Mearsheimer was an offensive neo-realist and believed states sought hegemony and that all states wanted to be regional hegemons. Thus, he believed that “overwhelming power is the best way to ensure one’s own survival”. Furthermore, Mearsheimer argues that it is difficult to estimate when states have reached their “satisfactory amount of power” and thus a balance of power like Waltz desires does not work as “logic of balancing ignores the problem of collection action”. (Wang, 2004, p. 178) Wang further highlights how this is seen “when threatened states have incentives to let others bear the costs of balancing the aggressor.” Whether a great power will balance or buck-pass depends on the distribution of power. Concluding from this, for “classical realists, power is an end in itself; for structural realists, power is a means to an end and the ultimate end is survival.”However, what are the criticisms for this neorealist ideology? Robert Keohone criticizes the theory due to Waltz’s definition of state interests. He considers that the “neorealist theories do not say anything about the prediction of state interests so since systematic theory cannot predict state interests, it cannot support deterministic conclusions” (1983, pp. 183). The other distortion of the theory is about the definition of power. It is difficult to measure the term of power. In Keohane’s perspective, there should not be one stable definition; he recommends that the definition should shape according to the problem (1983, pp. 191). I totally agree with this statement, because in the global world, military power does not mean anything without the other variables.In conclusion, the international political theory of realism is seen as “one of the oldest theories to international relations, and is widely held as a worldview” (Pease, 2012: 43). Its characteristics are still dominant, however, the theory is not unified in its approach as seen through its different variations. Classical realists focused on the internal state’s behavior. However, defensive realists such as Kenneth Waltz, focus more on the “world system and the ways the system limits or dictates behavior. So it is not about the behavior of the individual as it is about the importance of anarchy; anarchy is the reason that states act the way that they do.” (Burchill, 2001). Over the decades as globalisation made its impact in the political arena and the end of the Cold War initiated, criticisms for the theory grew. Thus, as realism conveyed outdated and excessively simplified ideas which had no room for the ideologies such as liberal internationalism which took better unto account the dramatically changing picture of global politics.