To attempt to answer the question of this essay I will give an account of the perspectives of prominent realist thinkers and of their analyses and predictions of how states relate to each other in the international arena. Subsequently, I will provide an account of the liberal perspective and its arguably idealist and to an extent limited impact on international relations. This will help explain why there is indeed a tension between these two schools of thought. This tension is both historical and contemporary, but I will conclude that it does not render these IR theories necessarily mutually exclusive, even though these perspectives have often been divided by a deep gulf in their accounts of human nature and that of political conduct and expectation. The realist perspective may well continue to be an apt and accurate account of actual state conduct, yet the inroads made by liberalism internationally can neither be ignored and are significant.Before setting out to answer the outlining question related to international relations (IR) theory, a brief and superficial remark on the general meaning of the term ‘realism’ may shed light. For the philosopher the term ‘realism’ implies on the whole an ontological opposition to nominalism and idealism. Even in common culture, such as for example in cinema and literature, we contrast realism with purely and overly escapist, fantastic or romantic treatment. This general definition and, admittedly simple account and understanding of realism brings us closer to providing an answer to the outlining question and will help to attempt to provide a meaningful and, hopefully, insightful answer. This is because in international relations theory, the theory of realism argues that the politics between nations are invariably determined by search for power for the sake of national interest. Given this brief definition of political realism, we have an initial foundation to contrast this outlook with that of ‘liberalism’. The term, as generally understood, is best defined by its Enlightenment meaning. It is a school of thought and ideology that believes that government should be limited and accountable for the sake of individual political and constitutional freedom and equality, self-determination, human rights and the beneficial nature of free market capitalism for societies. Arguably, these goals do not necessarily appear as unrealistic or idealist. Indeed, they appear to have become commonplace and are put forward by most governments in their official rhetoric. Hence, why should these two IR theories be potentially mutually exclusive? Perhaps because IR realists allege that liberals who aim to promote universal human rights, governmental accountability, international economic and cultural cooperation and perpetual peace merely engage in ‘wish-dreams’ and an ‘exuberance of utopianism’ that belies the actual state of world affairs. (Carr 2001: 14). Yet, the situation is more complex than a mere dichotomy of terms and theory and humanity has progressed in spite of its bellicosity.The realist position’s understanding of human nature can be expressed very well by Machiavelli’s saying that ‘all men are wicked and that they will always give vent to the malignity that is in their minds when opportunity offers’ (Machiavelli; Wootton 1995: 9). Similarly, Hobbes argued that we are in a continued posture of war of every man against every man and that life is solitary, nasty, brutish and short. (Hobbes 1994: XI-XIII) For Machiavelli the conclusion was that politics should be viewed not from the perspective of idealism and religious belief, but rather that a successful politics involves a sober and realistic assessment of the political status quo and the rallying of the population behind a powerful ruler and state. (Machiavelli; Wootton 1995: XIV-XV) For Hobbes, the conclusion was that the state of nature was a state of war and that only surrender to an absolute authority that creates law could provide peace. (Tuck 1989: 5-7) To explain the realist position, it is important to emphasize that both thinkers emphasized that, given the bellicose nature of human beings, self-interest underlies all rational and effective action.These considerations of inherent human egoism can be considered to apply only to the relations between individuals or smaller groups of individuals. Yet, as mentioned, this position which transfers ideas about our inherent human nature onto the international realm was essentially adopted generally by all subsequent realist theorists in IR. The reason is that the majority or realist thinkers in IR did not necessarily consider this pessimism about human nature as a universal and general theory of all politics, but specifically as a theory of IR. In essence, realism argues that we can draw conclusions and parallels between human nature and the political structure of international politics and that these prove to be uncannily accurate. (Morgenthau 1985; Waltz 1979)This shift of attention between human nature and the actuality of global politics lies at the heart of realist IR theory (Butterfield 1949: 31) It follows from this perspective that a coherent and accurate account of international politics must pay tribute to ‘the primacy in all political life of power and security’ (Gilpin 1986: 305). It also follows that given the natural rational egoism of human beings in the absence of an international government states must pursue a state-centrist course. In the international arena the type of absolute authority that Hobbes envisioned could bring peace simply does not exist. Hence, in an international arena that can be characterised as an international anarchy, states can be considered as rationally acting ‘units’ (Waltz 1979: 11) or even as ‘conflict groups’ (Gilpin 1996: 7) which will invariably pursue their national interest. As a matter of fact, small kinship groups or even states may impose restrictions on political rule, whereas in the international arena, under raison d’état, we have witnessed abhorrent actions. States have engaged in systematic and widespread atrocities which may well be considered unthinkable within the setting of smaller communities. The realist position defines the actual reality of international political conduct by ‘the limitations which the sordid and selfish aspects of human nature place on the conduct of diplomacy’ (Thompson 1985: 20) As Morgenthau says: ‘Realism maintains that universal moral principles cannot be applied to the actions of states’ (Morgenthau 1985: 9).One important reason for this apparent amorality or immorality of state conduct from a realist perspective is the absence of an international government which could impose universal morals or ethics. Structural realists in particular have given emphasis to this aspect and see international relations as a pure prisoner’s dilemma or zero-sum game. (Butterfield 1949: 89-90; Waltz 1979: 62–3) Thus, an amoral tendency towards self-help, self-interest and the search for increasing power would exist for the structural realist ‘even in the absence of aggressivity or similar factors’ (Herz 1976: 10). In an anarchical and intrinsically competitive system, actors behave under conditions of uncertainty with mutual suspicion. Each actor fears the other and hence increases their ability to protect themselves and each such step in turn is seen by the other actors as a confirmation of their suspicion resulting ‘in a spiral of illusory fears and “unnecessary” defenses’ (Snyder 1997: 17) Thus, having given a brief overview of realist theory, I will move on to provide a summary account of liberalism before providing an analysis of the compatibility and mutual exclusivity of both schools of thought. Locke said man is “free…absolute lord of his own person and possessions, equal to the greatest and subject to nobody”, and any legitimate government must from this perspective guarantee “the mutual preservation of their lives, liberties and estates, which I call by the general name, property.” (Locke ‘Second Treatise of Civil Government’, IX, 123) Locke believed that each individual is a property of him or herself only. Hobbes too was an individualist. He believed that we are like ‘atoms’, not to be understood in the modern scientific sense, which are in constant collision. (Tuck 1989: 89). Yet his conclusion was unlike Locke’s. For Hobbes only absolute surrender to an absolute authority could guarantee peace between these constantly warring human atoms. For Locke, on the other hand, all political authority had to gain and earn legitimacy given his view of human beings. Although Locke’s position was not intended as a political rallying cry, but rather a philosophical position, it can be seen as a foundation for those demands for fundamental natural rights that would lead to the great revolutions of the Enlightenment. The historical impact of liberal ideology cannot be underestimated. The American Declaration of Independence of 1776 and the American Constitution of 1787 stated: ‘we take these truths to be self-evident, that all men are created equal, and that they are endowed by their Creator with certain unalienable Rights, that amongst these are Life, Liberty and the pursuit of Happiness’. Yet, whereas for the American Declaration the rights of individuals were only a consequence of citizenship, the French Declaration of the Rights of Man and of the Citizen of 1789 asserted that ‘all men are born free and equal in their rights’. From now on, ‘man had rights and not merely as a citizen’ (Brownlie 1972:437)To explain the nature of liberalism it is fundamental to understand its view of human nature and its emphasis on the individual. Classical realists did acknowledge that the actions of individual politicians in the name of their state could explain certain aspects of international conduct. For structural realists states became the sole actors in the international arena. Yet for liberals individuals became the primary actors and all political conduct must take account of their importance. Tesón explains that for liberalism the ‘primary normative unit is the individual, not the state. The end of states and governments is to benefit, serve, and protect their components, human beings; and the end of international law must also be to benefit, serve, and protect human beings, and not its components, states and governments’ (Teson 1992: 54).  From this liberal perspective, it is the respect of individuals that creates domestic and international legitimacy of states. This liberal outlook had a fundamental impact on the external as well as internal relations of states. (Gardner 1990: 23–39; Zacher and Matthew 1995: 107–50). Once the belligerence of unitary state actors or conflict groups within international anarchy becomes limited in its excesses, we arguably enter a new era. (Bull 1977: 13) .” After the Enlightenment, government across Europe “became increasingly based on legal means and deliberative processes, and less on royal whims, prejudices, and status considerations” (Holsti 2004: 45)This outlook can be well expressed by Kant’s ‘Perpetual Peace’. In his essay he argued that although warfare is a regular feature of the human situation it is not necessarily natural. He pointed out that there are two ways to achieve perpetual peace. We can stop our belligerence and warfare or we can all end up in a graveyard. The latter, ironically, also symbolized perpetual peace. Thus, whereas realists consider the search for power and recourse to war as a rational pursuit in an international anarchical arena, for Kant warfare was irrational, whether domestically or internationally. It was unconducive to economic relations and to an extent unnatural as no human being desires the horrors of warfare or their own death (Kant 1970: 100). Unlike the pessimistic perspectives of Machiavelli and Hobbes, he shared Locke’s much more optimistic outlook on human nature. He believed in our innate ability to achieve progress and that we could realize our innate potential through the practice of our reason. (Hoffmann 1995: 159–77) We should not forget that realism and liberalism are mere theoretical perspectives. Human nature and international relations with all their complexity, turmoil and contingency do not fit neatly into such theoretical and ideological straightjackets. To curb the realist enthusiasm that it is the sole school of thought with an actual grasp on actual political reality we can point to important aspects of liberal thought that have significantly transformed the world of international relations.  Its idea that market capitalism is the best means to allocate resources efficiently globally and domestically. This idea has arguably transformed the world and made it ever more interconnected. Paine in his The Rights of Man argued that warfare as conceived as a rational pursuit of self-interest was ‘contrived’ to serve the interests of a small ruling class and to subdue the rights of individual citizens. Individuals merely desired peace, but they were burdened by increasing tax and bureaucratic apparatuses which served to collect revenue to further the parochial interests to the ruling elite. Hence, for liberals significant domestic and international improvements could be achieved by combining democratic government and free trade. (Howard 1978: 31-33) Once the world is considered to be constituted in a manner in which individuals take precedent over nation states then borders and barriers to trade become ever more insignificant or even irrelevant. This idea is not just an utopian wish dream but this project has been realized under the guise of the European Union. Just as Kant had predicted, ever closer economic collaboration and integration of democratic states and populations would create peace. (European Commission) This very idea formed the basis of the inception and foundation of the European Union as it was intended primarily to create closer economic and social ties between two longstanding foes, France and Germany, which had been at the centre of the two greatest wars the world had seen, arguably in history. By tying their coal and steel industries together, both of which were considered to be essential for their war apparatuses, it was thought that future warfare could be avoided. (Weigall; Stirk 1992: 11-15) Today it would be inconceivable that these two countries would consider going to war against each other. Indeed, it appears virtually inconceivable that any two members of the European Union would engage in warfare. Trade has become virtually frictionless between member states, they have all ratified a legally binding human rights agreement and borders are virtually transparent due to frictionless travel. The European Union has thus demonstrated that inroads can be made which are propelled by a liberal agenda that appears to undermine some of realisms more pessimistic claims of an intrinsic desire for perpetual human conflict.Also, considerable progress has been made under the auspices of the United Nations. It has made considerable progress in the promotion and protection of international human rights and has named and shamed governments which violate them systematically. It was in the wake of the Nuremberg trials that the United Nations created an International War Crimes Tribunal and it has since prosecuted various notorious war criminals. Also, since its inception we have arguably extended what has been termed the ‘liberal zone of peace’. It is arguably correct that hitherto no two democratic nations have engaged in warfare against each other. Doyle’s argument, however, does not rule out that democratic nations engage in warfare with undemocratic nations. Nevertheless, the liberal zone of peace has increased. (Doyle 1986: 1151, 1162; Doyle 1983: 323). Furthermore, we live in an ever more technologically interconnected world in which it becomes increasingly difficult for governments to hide gross and systematic violations of human rights or preparations for conflict. (Hobsbawm 2000) Nevertheless, ‘Westphalia’, as Rousseau once said, ‘will perhaps forever remain the foundation of our international system’ (Holsti 2004: 43). Rousseau’s comment relates to the peace treaty of Westphalia under which national sovereignty was cemented. Hence realists are correct in that we are not moving closer towards a universal cosmopolis. The nation state appears to remain for the foreseeable future the fundamental unit of the international political landscape. Indeed, the very idea on which the United Nations Charter system is based excludes any idea of a world government. Schachter points out that the sovereignty of states remains a ‘”logical consequence” without which there could be no durable operative system of law’ (Schachter 1991:10-11). Realists are therefore correct to emphasize the continued importance of sovereignty and the pursuit of self-interest in our current international legal system because ‘acceptance of the system is in itself a plausible basis for the obligation to abide by the particular rules valid in that system. Therefore the idea of a liberal utopia can be ruled out in that ‘’formal sources’ do not exist in international law. As a substitute, and perhaps equivalent, there is the principle that the general consent of states creates rules of general application’ (Brownlie 1972:2).The tension between realist and liberal perspectives can also be exemplified by the hopes and aspirations that arose after the demise of the Soviet Union and in the wake of the Arab Spring. After the fall of the Soviet Union Fukuyama foresaw a kind liberal triumph and that a global move towards democratic government would be unavoidable and would bring with it an international cessation of hostilities. Fukuyama was impressed by the degree to which liberal democracies had overcome their bellicosity and have increasingly relegated those norms which created a mere balance of power and merely curbed their propensity for warfare. This increase of liberal values signalled to him the arrival of a world made up of liberal democracies which ‘should have much less incentive for war, since all nations would reciprocally recognise one another’s legitimacy’ (Fukuyama 1992: XX) He also argued that ‘Liberal democracy may constitute the ‘end point of mankind’s ideological evolution’, and ‘the final form of human government’, and as such constituted the ‘end of history’’ (Fukuyama 1992: XI)Yet, Fukuyama’s predictions did not necessarily come to bear fruit. Arguably, we have witnessed an increase of the liberal zone of peace, but we have also seen an increase in the rise of ideological and religious fundamentalism in the wake of the Arab Spring and post-Soviet Russia has certainly not abandoned its real-politik. Many countries that had high hopes for their own Arab Spring movements and momentum have descended into chaos and the Soviet Union has annexed Crimea and has shifted its power politics into efforts of destabilizing governments and the electoral processes of liberal democracies. Hence, the tension between realist and liberal perspectives continues to exist and particularly neo-liberals would argue that liberal moral aspirations will continuously be undermined by the lack of an over-arching authority that can regulate state behaviour within states and in their relations towards each other. The anarchy of the international system does tend to create a certain degree of homogeneity in states’ behaviours and does seem to create a society of states to a certain degree, and at times this homogeneity may appear to correspond with liberal values, but such advances may be merely temporal.In the long run realists would assert that the search for power and security in a highly contingent and competitive world will always outweigh and override liberal moral and economic aspirations. Waltz, for example, argues that the liberal assumption that democratic domestic systems will inevitably result in peaceful foreign diplomacy and policy is a type of ‘reductionism’. It fails to acknowledge that the international system is characterized by ‘systemic’ aspects and features which override the ‘inside-out’ and ‘out-side’ perspectives of liberals (Waltz 1991: 667) Arguably liberalism has made inroads, but realists would argue that liberalist theory has merely established an account of the correlation of certain behaviours in international politics, but that it has not been able to establish a theoretical ‘iron law’ and that it fails to take into account the covert behaviour of states (Maoz and Russett 1993).Indeed, some realists would argue that the continued Hobbesian posture of war is an actually fare effective guarantor of peaceful relations. For realists the collapse of the Soviet Union signalled the coming of a period of potentially greater instability. From a realist perspective the balance of power provides a much greater stabilizing force than the expansion of the liberal zone of peace. Hence for Waltz ‘unbalanced power constitutes a danger’ in international politics. (Waltz 1991: 670) The fact that the world has witnessed continued political and military instability appears to confirm this realist incompatibility with the liberal outlook. Also, the growth of religious fundamentalism globally has proven that some states and societies do not consider liberalism as normatively superior and that they have little appetite of joining the so called liberal zone of peace. They consider it to be a parochial politics and a culturally dominating agenda that is at times incompatible with their own specific cultural perspectives and agendas. Hence, a cynical perspective could argue that one reason why many illiberal states have welcomed the growth of the liberal zone of peace and paid lip-service to it is not their desire to transform into liberal democracies but rather ‘the idea of limited power which is present within, but not entirely synonymous with, liberal democracy’ (Linklater 1993: 33-36).  Perhaps, as Morgenthau asserted, the pursuit of power in international relations is permanently imposed upon us as a law grounded in human nature which will forever provide the basis for the assessment of rational conduct in international relations. States and cultures are historically transient, emerge and wither away, but what remains is that the “workmanlike manipulation of the perennial forces that have shaped the past as they will the future” must be grounded in prudence and not morality. Or, if the pursuit of power “is the perennial standard by which political action must be judged”, then perhaps human rights are but the mere pursuit of particular interests disguised as noble moral aspirations (Morgenthau 1985: 12) As Carr pointed out: “these supposedly absolute and universal principles (peace, harmony of interests, collective security, free trade) were not principles at all, but the unconscious reflexions of national policy based on a particular interpretation of national interest at a particular time’ (Carr 2001: 111)From a realist perspective liberal inroads did not change the reality of international relations. Much of human society has been preoccupied by search for power and warfare, yet it is evident that realism in IR has to acknowledge the inroads made by liberalism. Liberalism and utopianism are also a remedy against “the barrenness of realism”. (Carr 2001: 93) The apparently perpetual lack of morals in international relations can become ameliorated once we consider our nature as a protean species that is capable to revise and shape our destiny. For Bull, order between states was merely “instrumental to the goal of order in human society as whole” (Bull 1977: 22)Warfare has not been abolished, but some of the greatest projects of human reconciliation and approximation have been introduced under liberal doctrine. However, an answer to the outlining question of this essay can be provided by Kant’s peculiar stance on the irrational and contradictory nature of warfare. He argued that although warfare is ultimately irrational and creates economic and social misery and division, the cessation of warfare can actually bring individuals and nations closer together. Peace can lead to reconciliation. This may appear contradictory, but if we survey the efforts of the League of Nations, which were arguably short lived, the United Nations’ enduring legacy, and the ever-closer integration of the European Union, then we can assert that a realist perspective and a liberal perspective are not necessarily mutually exclusive. The answer appears to be that both the realist and the liberal perspectives on human nature simply describe different aspects of the human situation and our political conduct therein. This applies to domestic as well as international politics. It is in view of this realisation that Bull argued that ‘the idea of the rights and duties of the individual person has come to have a place, albeit an insecure one and it is our responsibility to seek to extend it’ (Bull 1984: 12). To reconcile such a liberal and cosmopolitan utopia with the harshness of human nature described by realism should be the aspiration of all ‘intelligent and sensitive persons’ (Bull 1977: 289).               Bibliography:“A peaceful Europe – the beginnings of cooperation”. European Commission. https://europa.eu/european-union/about-eu/history/1945-1959_en; Retrieved 12 December 2018Brierly, James Leslie (1958) The Basis of Obligation in International Law and Other Papers, Clarendon Press (Oxford)Brownlie, Ian (1972) ‘The United Nations as a Form of Government’, Introduction to ‘The United Nations, 26th Session’, Harvard International Law Journal, Vol. 13Bull, Hedley (1977) The Anarchical Society, Macmillan (London)Butterfield, H. (1949) Christianity and History (London)Doyle, Michael W. (1986) ‘Liberalism and World Politics’, American Political Science Review, Vol. 80Fukuyama, Francis (1992) ‘The End of History and the Last Man’, Penguin Books (London)Gardner, R. N. (1990) ‘The Comeback of Liberal Internationalism’, The Washington Quarterly, 13(3).Gilpin, R. G. (1986) ‘The Richness of the Tradition of Political Realism’, inR. O. Keohane (ed.), Neo-Realism and Its Critics (New York)Herz, J. H. (1976) The Nation-State and the Crisis of World Politics: Essays onInternational Politics in the Twentieth Century (New York)Hobbes, Thomas (1994) Leviathan, Hackett (Indianapolis)Hobsbawm, Eric (2001) On the Edge of the New Century, The New PressHolsti, Kalevi Jaakko (2004) Taming the Sovereigns – Institutional Change in International Politics (: Cambridge University Press (Cambridge)Kant, I. (1970) Kant’s Political Writings, ed. H. Reiss, trans H. Nisbet (Cambridge)Linklater, A (1993) ‘Liberal Democracy, Constitutionalism and the New World Order’, in R. Leaver and J. L. Richardson (eds), Charting the Post-Cold War Order (Colorado)Locke, J ‘Second Treatise of Civil Government’, http://www.yorku.ca/comninel/courses/3025pdf/Locke.pdf, last accessed 20 Dec 2018Machiavelli, N., & Wootton, D. (1995). The Prince, Hackett Pub. Co.(Indianapolis)Morgenthau, Hans (1985) Politics Among Nations, Knopf (New York)Schachter, Oscar (1991) International Law in Theory and Practice, Martinus Nijhoff (Dordrecht)Snyder, G. H. (1997) Alliance Politics (Ithaca).Tesón, Ferdinand R.  (1992)  ‘Kantian Theory of International Law’, Columbia Law Review, Vol. 53Thompson, K. W. (1985) Moralism and Morality in Politics and Diplomacy (Lanham)Tuck, Richard (1989) Hobbes, Oxford University Press (Oxford)Waltz, K (1979) Theory of International Politics (Reading)Weigall, David; Stirk, Peter M. R. (1992). The Origins and development of the European Community. Leicester University Press. pp. 11–15Zacher, M. W. and Matthew, R. A. (1995) ‘Liberal International Theory: Common Threads, Divergent Strands’, in C. W. Kegley Jr (ed.), Controversies in International Relations Theory (New York)Get Help With Your EssayIf you need assistance with writing your essay, our professional essay writing service is here to help!Find out more