Discussing the “Core Themes” and “Principal Assumptions” of Realism – the Nuances of Post-Cold War International Relations

This article discusses “core themes” and “principal assumptions” in the realist study on international relations. It identifies some fundamental claims that distinguish realism from other theoretical perspectives. Moreover, it believes that the debate on the core of realism helps to clarify its understanding of contemporary international affairs. Yet the evolution of realism reveals a number of ambiguities in the picture of its “principal assumptions”. It warns that the list of realism’s “core themes” must be cautious and avoid simplifications. The article outlines some theoretical challenges that realism faces in the post-Cold War international reality and their impact on realism’s essence. It argues that further debate on realism’s “core themes” is valuable yet it needs a more nuanced attitude – far from simplified conclusions. Finally, the article proposes a nuanced catalogue of realism’s “principal assumptions” which reflects the complex nature of contemporary international relations.


Introduction
Realism has never been a consistent theoretical attitude to international relations. Yet scholars tend to identify some principal assumptions which could distinguish it from other theoretical perspectives. The debate is far from reaching a conclusion. Yet it helps to identify some "core themes" around which realist theories revolve and some fundamental claims which make the realist perspective recognizable in the study on international relations. This article believes that it is possible, useful and valuable to debate on realism's "first assumptions" and this debate helps to clarify realism's understanding of international affairs. Yet, the evolution of realism illustrates that the picture of its "principal assumptions" faces a number of ambiguities and inconsistencies. It was nuanced during the Cold War period and it is even more complex in the international reality after the end of the Cold War. It must be cautious and avoid oversimplifications.
Hence, the article identifies some "core themes" which recur in the realist understanding of international relations. Yet this paper indicates a number of disputes inside this paradigm on the principal causes and mechanisms of international processes. As this articles notes, even some concepts fundamental for realism may provoke different interpretations. This makes the list of realism's "core themes" nuanced and suggests caution when making general conclusions. Further, the article outlines some explanatory problems of realism after the fall of the bipolar order. The post-Cold War reality confronts it with some principal questions of how parsimonious a theory of contemporary international relations should be and how far to reach inside foreign policymaking processes. The challenges affect the picture of realism's "core themes" significantly and make the general conclusions even more problematic. Realism needs further debate on its fundamental theoretical assumptions. Yet their list must be careful and nuanced -far from simplified conclusions. Hence, the last part of the article proposes a catalog of such nuanced "principal assumptions" of realism -adequate to the international reality after the end of the Cold War. It is probably incomplete yet it might be useful for further study on realism and its understanding of international relations.
The article is divided into five sections. It indentifies the "core themes" that recur in the realist understanding of international relations (section two) and then reveals nuances and ambiguities around realism's "principal assumptions" during the Cold War (section three) and especially in the post-Cold War period (section four). The final section offers the picture of realism's "principal assumptions" adequate to the contemporary international reality. To reveal the similarities and ambiguities in the realist understanding of its "core themes" the paper compares different realist theories and their assumptions. This comparison, however, is aware of dynamics of international relations after the end of the Cold War which complicates the debate on the realism's core and faces the entire paradigm with serious theoretical challenges.

Identifying "Core Themes" in the Realist Understanding of International Relations
The essence of realism has been a subject of a long debate. It engaged prominent realists, critics of realism and some middle ground theoretical positions. It attracts attention of a number of contemporary scholars in both realist and non-realist camps. The views differ. They reflect different theoretical perspectives of their authors, different ontological and epistemological assumptions and even different historical contexts. They make the debate on the core of realism far from conclusion. Yet they still allow identifying a catalogue of problems which become fundamental for the realist understanding of international affairs. The catalogue of the "core themes" which recur in the realist considerations, irrespective of a variety of theories present in the realist paradigm in the recent decades. This list revolves around: = power and the struggle for power. Power remains a concept principal for realism and the realist understanding of international relations. For some realists a pursuit of power may be an aim in itself while all agree that it is a prerequisite for a state's effective foreign policy, its security and interests (Steans et al., 2010;Fernandes, 1991). It is, as Gilpin underlines, "the final arbiter of things political" (Gilpin, 1984, p. 290). In the same vein, international politics is about power and power remains its fundamental feature (Guzzini, 2004;Schweller and Wohlforth, 2000). The strive for their power "puts states at odds with each other" and the struggle for power is a basic mechanism of international relations (Trachtenberg, 2012, p. 3). It is a source of tensions and conflicts among self-interest states (groups) which make international politics a realm of "perpetual competition" for scarce goods and resources Walt, 1998).
= conflictual nature of politics. The struggle for power makes the nature of international relations "essentially conflictual" (Brooks, 1997;Gilpin, 1984). States' interests and preferences collide and transform international politics into a domain of constant competition or "a perpetual interstate bargaining game over the distribution and redistribution of scarce resources" (Legro and Moravcsik, 1999, pp. 13-16). Further, the presence of conflict in politics is unavoidable for realists and provokes violence and disorder in international relations (Morgenthau, 1948;Freyberg-Inan, 2004).
= selfish nature of humans, egoism of states and their preference for national interests. Human nature in the realist perspective is egoistic and selfish (Morgenthau, 1948;Freyberg-Inan, 2004). States in international relations focus on their own interests and pursue their own political aims -even to the detriment of others (Steans et al., 2010). They are egoistic and tend to consider international affairs in the context of their own relative gains. This selfish human nature and states' "appetites for power" explain, in line with Elman, "the seemingly endless succession of wars and conquest" (Elman, 2007, p. 11).
= the primacy of security issues over other areas of states' activity. The self-interest policy and fear of survival make security the principal and primary political motive of any state (Guzzini, 2004;Freyberg-Inan, 2004). States may consider a variety of other values and goals, but security remains a prerequisite and no other goal will be achieved unless a state's security is guaranteed (Fernandes, 1991;Gilpin, 1984).
= the prevalence of material and military aspects of power. The primacy of security issues in a state's foreign policy makes its material and military capabilities a fundamental aspect of a state's power (Steans et al., 2010;Legro and Moravcsik, 1999). Military capabilities are necessary to defend a state from a variety of external threats and provide its foreign policy with tangible material foundations. Hence, the military dimension receives a privileged position in the realist understanding of power and politics (Buzan, 1996).
= the group (state)-centric perspective. Realists consider international relations as a variety of interactions between political groups. Their focus on groups prevails over the attention paid to individuals or social classes since "(…) in a world of scarce resources and conflict over the distribution of those resources, human beings confront one another ultimately as members of groups, and not as isolated individuals" (Gilpin, 1984, p. 290). The principal social groups in contemporary international affairs are (nation) states. They are sovereign and independent units with no formal authority above them (Fernandes, 1991;Keohane, 1986). Thus, the relations among states constitute the essence of international politics and it is hardly possible to comprehend it without the attention paid to states (Legro and Moravcsik, 1999;Vasquez, 2004). = international anarchy and the self-help policy. The lack of any authority above sovereign states makes international relations anarchic. In other words, states act in the anarchic environment with no protection from any central and overarching world power (Elman, 1996). Anarchy is a permanent feature of the international reality and cannot be transcended (Schweller and Wohlforth, 2000). It fosters distrust, competition and conflicts in relations among states and makes their fears of security and survival even more serious. Finally, it contributes to the self-help policy as a guiding principle for a state's foreign and security policy (Elman 1996, Buzan 1996. = the problem of states' rationality and adaptability to external (systemic) constraints in the anarchic international environment. Some contemporary scholars do not consider rationality as essential to realism (Schweller and Wohlforth, 2000) yet realists tend to agree that states adapt to changing power relations in the anarchic international environment (Wohlforth, 1994/95;Lebow, 1994). This adaptation introduces some elements of rational foreign policy which identifies constraints imposed by the international system and selects a strategy that increases a state's chance for security and survival. It means that states weight different political options and chose those which foster their national interests (Vasquez, 2004;Legro and Moravcsik, 1999).
= limited effectiveness of international law and other mechanisms to regulate international relations. For realists the effectiveness of international law and international institutions is limited and depends on a game of national interests. Without consent of states the role of mechanisms developed to tame and moderate conflicts in international politics remains illusory (Lebow, 1994;Griffiths et al., 2008).
= skepticism towards pacifying legal and moral projects and harmony of interests in international relations. Realists are sceptical towards any "schemes for pacific international order" (Doyle, 1997, p. 43;Schweller and Wohlforth, 2000, p. 69). They reject utopian promises of the natural harmony of interests in international relations or moralist and legalist projects to overcome the struggle for power present in politics Legro and Moravcsik, 1999).
= the prevalence of national interests over (international) morality. Power calculations prevail over any moral considerations in the realist view of international relations when both values collide. Politics is much more about power and interests than about morality (Gilpin, 1984;Keohane, 1986). Besides, many realists tend to understand ethics and morality instrumentally as a product of power and a reflection of states' interests (Schweller and Wohlforth, 2000;Taliaferro et al., 2009). = pessimism regarding human conditions. Realists are pessimistic about the nature, conditions and progress of humanity as well as humans' ability to "transcend conflict through the progressive power of reason" (Schweller and Wohlforth, 2000, pp. 68-69). They doubt the elimination of conflicts from international relations and a world free from selfish and egoistic interests (Walt, 1998;Rosenthal, 1991).
= the tendency to associate major international changes with major wars. It is, in line with Wohlforth, a tendency among realists to consider great wars as the final test of a state's power. It is their skepticism that major international changes may occur peacefully (Wohlforth, 1994/95;Schweller and Wohlforth, 2000).

= clear links between theory and practice of international relations.
Realists agree that their theories should keep a reference to the real world, "real-life experiences" and practical problems (Rosenthal, 1991;Keohane, 1986). This is a realist tradition of "advice to princes" and a "pragmatic" function of realist theories to advice states on how to pursue their interests effectively in the egoistic world of international affairs (Gilpin, 1984;Schweller and Wohlforth, 2000).

The Nuances and Ambiguities around the Realism's "Core Themes"
The catalogue of the "core themes" of realism reveals a number of problems fundamental for any realist study on international relations. Yet the evolution of realism, and especially disputes between its classical and structural streams, illustrates that this picture may be more complicated. The controversies between the classical and structural renditions of realism, and mainly theories of Hans J. Morgenthau and Kenneth N. Waltz, will not invalidate the concept of realism's principal claims itself. Yet some clear differences around a prioritized level of analysis, parsimony of theoretical considerations or causal variables make the picture of the "core themes" more nuanced. The disputes encourage some restraint while making assumptions about what the core of realism actually is.
Indeed, a simple look at the causes behind the struggle for power reveals a different emphasis made by Morgenthau's classical realist perspective, which favours the lust for power rooted in human nature, and Waltz's structural theory which indicates international anarchy and the self-help policy as the source of conflicts in international affairs (Steans et al., 2010;Schweller and Priess, 1997;Lee, 2018). Classical realist attitude did not introduce a clear distinction between foreign policy issues and problems of international politics. It considered a variety of domestic and individual aspects of foreign policymaking and recognized historical, social or even cultural contexts of international processes (Schweller and Priess, 1997;Lebow, 2003). It emphasized "agents along with structures" as well as leaders' dilemmas and hardly predictable nature of politics (Lebow, 2007;Steans et al., 2010;Rösch and Lebow, 2018). Classical realism focused on relative power relations between two states (dyadic) or groups and coalitions of states and less on "the system-wide distribution of capabilities" (Schweller and Priess, 1997;Schweller, 2003).
Structural realism, and mainly Waltz's structural approach, aspired to a more rigorous theory at the level of the international system (Elman and Jensen, 2014). It focused on the distribution of power in the system and its polarity (Schweller, 2003;Lebow, 1994). It considered the impact of systemic forces (constraints and incentives) on a state's foreign policy and some general patterns of how different systems work Elman and Jensen, 2014). Hence, Waltz's theory abstracted from any unit and individual level considerations. It was uninterested in internal characteristics of states, considerations about human nature, dilemmas of political leaders or ethical aspects of politics (Walt, 1998;Lebow, 1994). It was, as Annette Freyberg-Inan underlines, an attempt to build a theory of international politics based exclusively on the third-image (systemic) variables "without paying attention to first-image (psychological) or second-image (state-level) variables" (Freyberg-Inan, 2004, p. 73).
Further, the evolution of realism illustrates that even some concepts obvious for realists like power, the struggle for power or a state's security may provoke ambiguities and different interpretations. A clear example in this regard is the group-centric nature of international relations and the claim that states remain the dominant political actors in contemporary international affairs. Both assumptions are obvious for realism (Gilpin, 1984;Legro and Moravcsik, 1999) yet for some (classical) realists states do not have to be the ultimate type of social organization. The evolution of social, economic, demographic or cultural processes may change the present nature of states and bring about new forms of social association (Elman, 1996;Gilpin, 1984). It means, in line with Duncan Bell, that "At certain times and in certain places, the state may be the most significant actor in world politics, but this may change" (Bell, 2008, pp. 10-11). Thus, realism remains group-centric yet it is "(…) not theoretically committed to any particular type of political association" (Bell, 2008, pp. 10-11) and, in line with Morgenthau, "Nothing in the realist position militates against the assumption that the present division of the political world into nation states will be replaced by larger units of a quite different character, more in keeping with the technical potentialities and the moral requirements of the contemporary world" (Morgenthau, 2006, p.12).
Consequently, the claim that states are unitary actors, typical of the Waltz's structural theory, provokes controversies in the realist camp. The assumption that "(…) states speak with one voice, and any internal disputes are resolved before a foreign policy is implemented" (Fernandes, 1991, pp. 44-45) has previously been questioned by classical realists and now is criticized by the new stream of neoclassical realism. The former, including Morgenthau, note the role of political leaders and a variety of political (and ethical) dilemmas that the leadership faces while deciding about a state's foreign policy (Morgenthau, 1947;Neacsu, 2009;Rösch and Lebow, 2018). The neoclassical stream of realism emphasizes that both a perception of power and a game of domestic interests may ultimately affect the final form of this policy (Rose, 1998;Taliaferro et al., 2009). In the same vein, neoclassical realists disagree with the structural realist claim that states easily extract all resources (all components of power) at their hands to support their foreign policy aims or with the assertion that "States faced with a similar strategic situation will extract a similar proportion of domestic resources" (Legro and Moravcsik, 1999, p. 17). In the neoclassical realist perspective the leadership's access to a state's resources is more problematic and may provoke domestic resistance, especially if official political aims collide with social expectations or cause social and economic costs (Rose, 1998;Schweller, 2003). Finally, some realist conclusions on the "secondary importance" of non-state actors seem ambiguous in contemporary international affairs. Even if states dominate on the international scene their relations with non-state actors, and mainly transnational corporations, would require more attention and some deeper realist reflection (Vasquez, 2004). Thus, in line with Dunne and Schmidt, the extent to which non=state international subjects "are autonomous from state power" remains unclear in realism (Dunne and Schmidt, 2001).
Moreover, all realists emphasise conflict as the permanent feature of any political activity. All warn about potential violence that may accompany international politics. Most realists, however, indicate that conflict in politics must be tamed and moderated (Bell, 2008;Rösch and Lebow, 2018). They call for prudence and restraint in a state's foreign policy which could reduce the war=prone nature of international affairs and keep the destructive aspects of human nature checked (Freyberg-Inan, 2004;Trachtenberg, 2012). In this perspective, in line with Marc Trachtenberg, politics is less about coercion and more "about striking balances-about weighing benefits against costs, about assessing risks and dealing with uncertainty, about deciding how much is enough and how much is too much" (Trachtenberg, 2012, p. 28). Besides, some realists (and mainly classical again) indicate that common values or shared cultural norms may contribute to this restraint. They are still far from a constructivist focus on identities or a liberal community of interests yet some elements of international society are not completely strange for realism (Lebow, 2003). Hence, in line with Michael C. Williams, "(…) a recognition of the centrality of power in politics does not result in the reduction of politics to pure power, and particularly to the capacity to wield violence". Realism may as well seek "(…) a politics of limits that recognises the destructive and productive dimensions of politics, and that maximises its positive possibilities while minimising its destructive potential" (Williams, 2005, p. 7).
Yet even the world of states that pursue their national interests may not necessarily be the world of brutal violence and aggression. The states which are sensitive to and understand power relations on the international scene may avoid risky strategies and prefer a moderate foreign policy. The political strategy based on power and interests may therefore be a source of restraint as well (Trachtenberg, 2012;Rösch and Lebow, 2018). It reflects Morgenthau's previous considerations about the concept of the national interest which helps to make a distinction between a state's primary and secondary aims and understand motives of other states (Morgenthau, 1952).
In the same vein, a simple contention that realism is an amoral theory that disregards any ethical norms is misleading (Neacsu, 2009;Fernandes, 1991). It is true that structural realism paid no attention to normative considerations as detached from its concept of "scientific theory" (Bell, 2008).Yet the lack of interest in moral and ethical aspects of international relations did not automatically mean completely amoral character of Waltz's structural realist considerations. Moreover, the normative aspects were at the centre of classical realist studies. Classical realists were aware of competing impulses from ethics and power that accompanied any political activity (Gilpin, 1984;Rosenthal, 1991) and, in line with Joel H. Rosenthal, tended to see "shades of grey" where their opponents "saw only black and white" (Rosenthal, 1991, p. 32). For Morgenthau (as previously for Reinhold Niebuhr) any political decision revealed tensions between political effectiveness and moral claims. The former usually prevailed yet it was still the responsibility of political leaders to try to reconcile both competing impulses (Morgenthau, 1945).Thus, moral limitations accompanied classical realist studies on political moderation and could help to tame the most brutal aspects of power politics (Freyberg-Inan, 2004). Realism is still about power and power calculations may prevail over moral claims when both values collide, but it does not mean that realism is an amoral (and immoral) theory (Neacsu, 2009;Rosenthal, 1991).
Furthermore, all realists agree that security remains a state's primary goal, yet they disagree about a most effective strategy to secure a state's survival in the conditions of international anarchy. For offensive structural realists the most appropriate strategy is to maximize a state's power. This maximization is an obvious consequence of the self-help nature of international relations which encourages states to increase their capabilities "vis-a-vis other states" (Mearsheimer, 2001;Freyberg-Inan, 2004). Defensive structural realists accept the fundamental importance of a state's security and survival. Yet they assume that states may favour an "appropriate and satisfactory" amount of power and will not aspire for its maximization (Brooks, 1997;Trachtenberg, 2012). The defensive, moderated and predictable foreign policy may, in certain circumstances, result in a more secure international environment since it does not provoke unnecessary tensions. Thus, in some cases, the power maximization strategy may be self-defeating in the defensive realist perspective. (Taliaferro, 2000/01;Walt, 1998).
In the same vein, military aspects prevail in the realist understanding of power. Yet, in line with Stephen G. Brooks, offensive and defensive structural realists put different emphasis on interactions between military and economic purposes of a state's foreign policy, especially when both goals collide. Offensive realism favours military preparedness and tends to subordinate economic objectives to military aims. Defensive realism prioritizes military power as well but remains more open to a variety of "trade-offs" between military and economic goals. They reflect the level of a state's security and the probability of conflict rather than its possibility (Brooks, 1997). Besides, realists favour the material dimension of power and claim that states must "rely on their own resources" (Legro and Moravcsik, 1999;Trachtenberg, 2012). Yet for classical realist authors power is much more complex phenomenon which combines its material and psychological aspects (Wohlforth, 2011). In the view of Morgenthau, the concept of power encompasses some hard material components but also much less tangible aspects like the quality of a state's diplomacy, national character or national morale (Lee, 2018). Thus, power is still about "the ability of states to coerce or bribe their counterparts" (Legro and Moravcsik, 1999, p. 17). Yet it is also "(…) a psychological relation between those who exercise it and those over whom it is exercised (…)" (Morgenthau, 1948, p. 14). It means that a simple comparison of states' material capabilities may say little about their real power (Dunne and Schmidt, 2001).
Finally, realists disagree on rationality of a state's foreign policy and the picture of the rational state that "evaluates policy options according to a cost-benefit analysis in which its preferences are clearly prioritised" (Fernandes, 1991, pp. 44-45) is not a conventional and shared position of realism. Morgenthau's comprehensive understanding of power and his warnings about unpredictable nature of politics reduce the rational character of a state's foreign policy. Decisions of political leaders reflect a complex game of pressures and counter-pressures, including ethical and moral ones (Lebow, 2003;Buzan, 1996). Hence, "The best the scholar can do" is "to trace the different tendencies which, as potentialities, are inherent in a certain international situation" (Morgenthau, 1948, pp. 6-7). Waltz's structural theory introduces more rationality to a state's foreign policy since this policy is affected by a number of constraints imposed by the international system. It reflects the state's place in the system and its attempts to adapt to systemic conditions (Schweller, 2003;Wohlforth, 1994/95). The impact of the system may not be entirely deterministic since it affects states "through the processes of socialization" that rewards the policy which reflects a state's places in the hierarchy of power and punishes the policy which reaches beyond its material capabilities (Schweller, 2003;Schweller and Wohlforth, 2000). Yet, at least for less powerful actors, this socialization may leave no other practical choice than to respect the impulses from the system accurately (Herrmann and Lebow, 2004;Gilpin, 1984). It may impose a rationality which is, in line with Buzan, less "a human attribute" and more "a behaviourally engineered quality of actors within an anarchic political system" (Buzan, 1996, pp. 54-55).
As a result, the picture of realism's "core themes" is more nuanced than some general and conventional claims. The evolution of realism, to include its disputes during the Cold War period, illustrates that the debate on some fundamental problems and assumptions of realism needs cautiousness. It proves that the list of realism's "core themes" must be more nuanced and avoid oversimplifications. The international reality after the end of the Cold War makes this picture even more complicated. The fall of the bipolar order marked a serious challenge for realism, and especially its structural theories. It faces realism with some new theoretical problems which make the debate on its "principal assumptions" even more ambiguous.

Identifying Realism's "Principal Assumptions" in the Post-Cold War International Reality
The fall of the Soviet Union and the peaceful ending to the Cold War astonished, as John L. Gaddis indicates, "(...) almost everyone, whether in government, the academy, the media, or the think tanks" (Gaddis, 1992/93, p. 5). Yet it provoked a fierce criticism of realism and especially the Waltz's structural theory. Waltz's claims about a lasting stability of the bipolar order and difficulties in understanding domestic process in the Soviet Union in the late 1980s made his structural perspective unable to explain the end of the bipolar confrontation (Lebow, 1994;Wohlforth, 1994/95). Besides, they strongly suggested that the narrow structural (systemic) approach would not help realism in understanding post-Cold War international affairs.
Further, the end of the bipolar confrontation contributed to the emergence of new theoretical approaches (constructivism and a number of post-positivist theories) interested more in ideas, identities, beliefs or cultural and social norms than in hard empirical aspects of international relations (Brooks and Wohlforth, 2000/01;Kavalski 2018). This translated into a tendency to reflectivism in the study of international affairs and a growing plurality of theoretical perspectives -exaggerated and controversial for some contemporary scholars (Sterling-Folker, 2009;Waever, 2010). The globalizing international reality after the end of the Cold War marked openness to new social and economic problems -distant from the previous understanding of politics and provoking a debate about hybridity of the IR discipline (Waever, 2010).

Realism responded to Post-Cold War international relations with two new attitudes -Elaborated Structural
Realism and neoclassical realism. Both agreed that the paradigm must depart from the parsimonious perspective of Waltz. Yet both differed in their views on how far this departure should be. Elaborated Structural Realism (ESR) aspired to a new systemic perspective, broader than the distribution of power in the international system alone (James, 2009). A state's place in the hierarchy of power was still important yet ESR introduced some new systemic variables, including a concentration and dispersion of power and a geographical context of power relations in the system (James, 1993;Freyberg-Inan et al., 2009). Further, it accepted some systemic effects of states' interactions, including a number of alliances, and noted that even some states' motives (fears, ambitions or restraint) may ultimately affect power relations in the system (James, 1993;James, 2009). The latter allowed to address the previous parsimony of the Waltz's structural theory by "(…) allowing intentions to complement capabilities" (James, 2009, p. 57). Yet Elaborated Structural Realism remained cautious towards domestic (unit-level) variables. It preferred a consistent systemic attitude to contemporary international relations and declared that any unit=level factor it is going to consider must retain systemic consequences and a capability-based logic (James, 1993). For some realists this theoretical integrity was important yet for others it was disputable whether the systemic attitude alone would actually help realism to comprehend the dynamics and nuances of post-Cold War international affairs.
Neoclassical realism shares the general conclusion that a state's place in the international system affects jpl.ccsenet.org Journal of Politics and Law Vol. 13, No. 1;2020 ambitions of its foreign policy. Yet structural impulses may be ambiguous and are "filtered" in the neoclassical realism perspective through a "domestic transmission belt" (Elman and Jensen, 2014). The latter encompasses a variety of domestic (unit and personal levels) variables = much broader than in Elaborated Structural Realism (Rose, 1998;Taliaferro et al., 2009). Hence, neoclassical realism refers to political characteristics of states and nature of their leaders. It emphasizes a perception of power by leaders since, as Gideon Rose indicates, "Foreign policy choices are made by actual political leaders and elites, and so it is their perceptions of relative power that matter, not simply relative quantities of physical resources or forces in being" (Rose, 1998, pp. 146-147).
Besides, it notes that leaders often bargain with different domestic social forces which may affect the final form of a state's foreign policy . Thus, the impact of systemic constraints on this policy is indirect in the neoclassical realist view and in the medium and short perspective a state's foreign policy "(…) may not necessarily track objective material power trends closely or continuously" (Rose, 1998, pp. 146-147).
Neoclassical realism's openness to a variety of domestic variables marks a clear departure from the picture of states as unitary and rational actors (James, 1993;Schweller, 2003). It helps to analyse dynamic nature of post-Cold War international processes. Yet it confronts the neoclassical stream with some clear challenges, including inconsistency of its considerations and a limited ability to formulate any general theoretical conclusions (James, 2009). It provokes a question of how parsimonious contemporary realism could and should be. Further, a tendency among some neoclassical realists to delve into psychological aspects of foreign policymaking or social and political identities confronts neoclassical realism with some risk of reflectivism . It asks another question of how much from domestic determinants of a state's foreign policy realism should actually understand (Herrmann, 1997;Sterling-Folker, 2009).Finally, it provokes a criticism of neoclassical realism, like that by Legro and Moravcsik, of undermining the "core" assumptions of realism and seeking "(…) to address anomalies by recasting realism in forms that are theoretically less determinate, less coherent, and less distinctive to realism." (Legro and Moravcsik, 1999, p. 6).
In consequence, realism faces a clear dilemma. On the one hand it needs to avoid the rigidity of Waltz's structural theory and reach for new processes of domestic nature. This absorption may be inevitable, and the question is not whether to absorb some unit-level variables but where the borderline for this absorption is (Herrmann, 1997;Freyberg-Inan et al., 2009). Yet on the other hand it risks, in line with Legro and Moravcsik again, to be "stretched to include assumptions and causal mechanisms within alternative paradigms, albeit with no effort to reconcile the resulting contradictions" (Legro and Moravcsik, 1999, pp. 6-7). Contemporary realism is far from a definitive answer to this question. Yet the dilemmas it faces complicate the previous debate on realism's "core themes" even further. They prove that the new picture of its "principal assumptions" should be more dynamic, complex and nuanced. It must be cautious and comprehensive -even more than the disputes inside the realist camp during the Cold War period. Thus, how this new picture could finally look like? This article considers that: First, politics is still about power and the struggle for power. Power remains the key to identifying and pursuing any of a state's interest and the effectiveness of a state's foreign policy still depends on its (material) capabilities (Legro and Moravcsik, 1999;Taliaferro et al., 2009). Yet the reality of post-Cold War international relations encourages a return to some classical realist inspirations and a broader picture of power which accepts some of its non-material (or less tangible) aspects (Fernandes, 1991;Wohlforth, 1994/95;Lee, 2018). The inconsistent, ambiguous and reactive nature of Gorbachev's perestroika (and the fall of the Soviet Union in general) illustrates that the material perspective alone will not explain nuances of contemporary international affairs (Snyder, 2011). The focus on material power or a simple comparison of states' material capabilities may not say much about actual power relations on the international scene (Dunne and Schmidt, 2001). Thus, the complexity of contemporary international relations makes the static (positional) perspective of power problematic. It suggests a more nuanced and context-oriented attitude open to potential misperceptions and limited predictability of power calculations in the international system (Herrmann and Lebow, 2004;Schweller and Priess, 1997). It warns, in line with Morgenthau's previous considerations, that power "(…) is never anything stable, anything which is defined once and for all, but is in constant flux and it must always be conceived in relative terms" (Neacsu, 2009, p. 120).
Second, politics remains conflictual. States' preferences are antagonistic yet this picture is nuanced in contemporary international relations -opened to some forms of trade-offs and a variety of states' interests. The competition among states may differ according to their place in the system (Elaborated Structural Realism) or different perceptions of threat in different power configurations (neoclassical realism) (Brooks, 1997;Steans et al., 2010). Even in the view of Legro and Moravcsik "(…) the assumption of fixed, uniformly conflictual preferences need not mean that every set of state preferences actually are conflictual" (Legro and Moravcsik, 1999, p. 16). Besides, conflicts may and should be moderated. The departure from the Waltz's "structural determinism" and the openness to leaders' agency in post-Cold War international relations revive the previous debate on a variety of limitations on the struggle for power -even if the presence of conflict in politics is permanent for realists (Freyberg-Inan, 2004;Trachtenberg, 2012).
Third, sovereign states remain the principal subject in contemporary international relations and the role of non-state actors is secondary for realists Dunne and Schmidt, 2001). Yet a simple contention that NGO's or transnational corporations are of secondary importance becomes trivial and needs a more context-oriented response of realism -especially in the face of contemporary global economic processes (Elman, 1996;Fernandes, 1991). Thus, the nation states are still the main international actors, but they gradually lose their absolute domination and realism needs a more nuanced explanation of what their leading role actually means. In the same vein, the assumption that states are unitary actors seems too general in contemporary international relations and needs some reconsideration. It emphasises a "privileged position" of a state's "official authorities" to define and implement its foreign policy ). Yet it misses the classical and neoclassical realist research on different domestic social and political forces and their impact on the final form of this policy. It ignores uncertainty, inconsistency or mistakes in leaders' decisions as well . Certainly, the question of how much (and under what circumstances) domestic social forces affect a state's foreign policy needs further research. Yet the realist tendency to assume that states "speak with one voice" in international relations (Fernandes, 1991) requires some caution and reservation.
Fourth, security concerns and military considerations remain fundamental for any foreign strategy. Yet the primacy of security issues may be more nuanced in contemporary international relations. In line with Brooks, states may decide on some bargaining between "hard security" requirements and other aims, mainly those of economic nature (Brooks, 1997). The trade=off may depend on a level of insecurity in the system and a state's perception of its international environment. States are still responsible for their own security and some recent conflicts on the outskirts of Europe illustrate that the security environment may change rapidly even in the areas considered to be stable and peaceful. Yet the post-Cold War international reality makes the security considerations more flexible and comprehensive than during the Cold War period (Brooks and Wohlforth, 2000/01). Finally, contemporary international relations strongly confirm that military capabilities, even if still of utmost importance for realism, must be considered in close relations with their economic and technological foundations and even some less tangible aspects of power (international image) (Brooks, 1997;Buzan, 1996).
Fifth, the experience of the fall of the Soviet Union proves that the realist analysis of contemporary international relations must reach beyond the systemic level alone. In the same vein, the Waltz's division between theories of international politics and those of foreign policy becomes artificial and, in line with Schweller, unproductive and "unsustainable on logical grounds" (Schweller, 2003). It does not mean that systemic (structural) constraints of a state's foreign policy lose their significance yet it means that the analysis of a state's foreign policy needs a reference to both systemic and domestic variables (Brooks, 1997). In some cases the structural constraints may prevail yet it seems unwise to close contemporary international affairs into some systemic models and systemic frames. Thus, in line with Buzan, realism "operates on all three levels" of analysis (Buzan, 1996).
Sixth, the question of rationality of a state's foreign policy becomes much more complicated in the post-Cold War international reality. It means that states may not chose the best political option available (according to costs and benefits) and their foreign policy may not be the optimal one in the international environment they function (Fernandes, 1991). They may not easily adapt to systemic constraints since the constraints themselves may be more complex than several decades ago (Lebow, 1994;Wohlforth, 1994/95). The post-Cold War openness to unit-level variables, to include leaders' perception of power, makes the rationality less the adaptation to systemic (structural) determinants and more a quality of statesmen. It becomes more "a human attribute" (Buzan, 1996, pp. 54-55). Yet becoming the area of the statesmen' activity this rationality will inevitably face a variety of mistakes, inconsistencies and misperceptions in the leaders' decisions. They may not be decisive for a state's foreign policy yet they modify the rationality assumption. Thus, in line with James, the "(...) rational, unitary behavior at the international level cannot be assumed for all times and places" (James, 1993, pp. 125-126). 2011). Thus, realism may still be sceptical towards new ideas of this cooperation. Yet, in line with Charles L. Glaser, in some cases states may reach for international institutions to achieve their goals and "(...) when conditions facing a state make an international organization the best means available, realism should predict that states will develop and use it" (Glaser, 2003, p. 409). Besides, it reminds that to moderate and tame the struggle for power has always been the essence of realism -equal to conflictual and self-help nature of politics itself.
Finally, (and eighth) the links between theories and practice of international affairs remain fundamental for realism. They help to keep a distance from all ambitious political projects which promise harmonious international relations but forget about the game of national interests behind them (Legro and Moravcsik, 1999;Taliaferro et al., 2009).

Conclusion
Realism is not a consistent theoretical attitude to international relations, yet it is still possible to indicate some of its "core themes" and "principal assumptions". They revolve around power and the struggle for power, egoistic politics of states, the primacy of their security and national interests as well as anarchic nature of international affairs. They help to distinguish realism from other theoretical attitudes in the study on international relations. Yet the disputes between different streams of realism, and mainly its classical and structural perspectives, contributed to some ambiguities around the realist fundamental claims. The evolution of realism illustrated that the picture of its "principal assumptions" must be more nuanced and avoid oversimplifications. Besides, even some fundamental concepts of realism (power, security) may provoke some ambiguities.
This article believes that it is still possible, useful and valuable to debate on realism's "first assumptions" and the debate helps to clarify realism's understanding of international affairs. Yet the post-Cold War international reality makes this debate even more complicated. It reflects problems of realism with its response to dynamics and complexity of contemporary international relations -as illustrated by disputes between Elaborated Structural Realism and neoclassical realism. It is still important for realism to identify a catalogue of its "first assumptions" yet the latter need reconsideration. Further discussion on realism's fundamental theoretical claims needs cautiousness and a more comprehensive approach -far from oversimplified conclusions. This article proposes such a flexible and nuanced picture of realist "principal assumptions". It is certainly not exclusive and complete. Yet it may be useful for further studies about the essence of realism after the fall of the bipolar order.