Considering Rationality of Realist International Relations Theories

The article refers to debates inside realism on rationality of international processes. It reveals that even a basic assumption of states calculating their interests and choosing optimal political strategies provoked contradictions among realist theories. Both prominent Cold War realists, Morgenthau and Waltz, differed in their views on the role of leaders, the impact of the international system and states’ rational response to systemic constraints. The hegemonic rivalry stream of realism took the “middle ground” in this debate. Yet, the complex international reality after the fall of the bipolar order makes the realist considerations even more difficult. It encourages a wider openness to domestic nuances of foreign policymaking but reduces a chance for more general and rational schemes of states’ international behavior. Post-Cold War realists declare a need of systemic and rational frames of their analysis but differ in their views on how much of the domestic context should be absorbed to comprehend contemporary international processes. The integration of miscalculations and misperceptions in leaders’ political decisions and the rational frames of a state’s foreign policy is a clear problem for realism.


Introduction
The aim of this article is not to elaborate on the concept of rationality itself. Neither does it consider the nuances of rational choice theory. The paper focuses on different views on rational political action present in the realist paradigm. It discusses the attitude to rationality of a state's foreign policy present in different realist theories. Hence, the article refers to a basic (positivist-oriented) understanding of rational action which expects that states calculate their interests and choose a foreign policy optimal to achieve their intended goals (Elman 1996: 20-21). That they "select a strategy by choosing the most efficient available means to achieve their ends" (Legro and Moravcsik 1999: 12). The paper discusses rationality that in the systemic understanding of international relations translates into a foreign policy which adapts to a state's power and its place in the international system (Lebow 1994: 273;Wohlforth 1994Wohlforth /1995. This is the policy which respects systemic constraints and properly reads impulses coming from the system (Elman 1996: 20-21;Vasquez 2004: 156;Fernandes 1991: 44-47).
Yet, in the case of realism, even such general understanding of rationality provokes controversies and a lack of consensus. The evolution of realism during the last several decades reveals that it has never been unified in its view on a state's rational foreign policy and rationality of international relations in general. The theories of Hans J. Morgenthau and Kenneth N. Waltz, two prominent Cold War realists, reveal different attitudes to rationality of a state's international activity. They illustrate clear tensions between universal and particular aspects of international processes which accompany realist theoretical considerations. Both scholars look for some general (universal) rules of international relations and both expect that states will rationally adapt to them. Yet, for Morgenthau, a state's rational response to "universal laws" of politics is more an attribute of its responsible leadership than any "…behaviourally engineered quality of actors within an anarchic political system" (Buzan 1996: 54-55). Morgenthau accepts that some unit-level variables (domestic and individual) may affect the form of a state's foreign policy and believes that politics will never be (fully) predictable (Morgenthau 1948: 6). Hence, rationality of international processes in Morgenthau's theory is limited, context-oriented and (potentially) determined by some domestic attributes of states and their leaders.
The Waltz's systemic (structural) attitude looks for more theoretical unity, rationality and similarity of states' response to systemic constraints of their foreign policy. A state's place in the hierarchy of power affects its foreign activity much deeper than abstract Morgenthau's "laws of politics". Further, Waltz aspires to formulate more verifiable schemes of states' international behavior since "To the extent that dynamics of a system limit the freedom of its units, their behaviour and the outcomes of their behaviour become predictable" (Waltz 1979: 71-72). The return to the bipolar confrontation at the end of the 1970s encouraged a more rigorous systemic picture of a state's foreign policy which rationally calculates interests and power relations in the international system. Yet, Waltz's attempt to enclose international relations in a few general theoretical claims appeared parsimonious, rigid and unable to analyze dynamic international processes at the end of the 1980s. It missed, as the hegemonic stream of realism indicated, that units in the system could rise and fall in response to a variety of causes, including those of domestic nature.
The post-Cold War reality makes the realist debate on rationality of international affairs even more complicated. Its dynamics and complexity open more space to unit-level variables, including misperceptions and miscalculations of leader's political decisions. They become inevitable to understand the nuances of contemporary international processes, yet they reduce the previous expectations that states will rationally read impulses and constraints from the international system (Freyberg-Inan et al. 2009a: 6). As a result, realism is faced with some challenges and dilemmas. It accepts the role played by motivational variables but intends to retain some rationality and coherence of the systemic perspective. Yet, the realist response is ambiguous. Elaborated structural realism would like to defend the systemic unity and remains reluctant to an abundance of unit-level variables. Neoclassical realism reaches for domestic factors much deeper but risks no general and rational perspective of a state's foreign policy. Neoclassical realism declares a synthesis that would integrate intentional aspects of contemporary international processes and some rational patterns of a state's response to systemic constraints of its foreign activity. The latter idea is interesting (and refers to some previous Morgenthau's considerations) but needs further elaboration.
The article consists of seven parts. It reviews the approach to rationality of international processes present in subsequent realist theories. In its reference to the Cold War period, the paper focuses on Morgenthau's and Waltz's considerations as distinct theoretical approaches. It then discusses hegemonic rivalry theories which, in my view, take the "middle ground" in the debate on rationality of international affairs. Referring to considerations of post-Cold War realism, the article focuses on the elaborated structural stream and neoclassical realism as two leading realist perspectives after the fall of the bipolar order. Finally, it refers to dilemmas which realism faces while debating on rationality of post-Cold War international processes and problems of realism with identifying what political rationality means in the complex reality of contemporary international relations.

Rationality of International Relations in Morgenthau's Theoretical Considerations
Morgenthau aspired to formulate a consistent theory of international relations able to identify fundamental mechanisms and general rules of international processes (Buzan 1996: 48). He aimed at a theoretical attitude based on some fundamental "laws" of politics. To understand them meant to comprehend the international reality and to purse a state's foreign policy rationally and effectively (Gaddis 1992(Gaddis /1993Griffiths et al. 2008: 268-269). Hence, Morgenthau based his theoretical considerations on the fundamental concepts of the "lust for power", rooted in human nature, and the struggle for power (Morgenthau 1948: 13-21, 343-346;Scheuerman 2009: 37-38). Both became principal mechanisms of politics and the universal features of any political activity, including international relations (Lebow 2003: 224;Morgenthau 1948: 4, 21-22) Both were the objective "laws of politics" since "Political realism believes that politics, like society in general, is governed by objective laws that have their roots in human nature (Morgenthau 2006: 4). Thus, any foreign policy that aspires to be rational and effective needs first "…to understand the laws by which society lives. The operation of these laws being impervious to our preferences, men will challenge them only at the risk of failure" (Morgenthau 2006: 4). Further, any rational foreign policy in Morgenthau's theoretical considerations needs to follow the principle of the national interest. The concept of the national interest becomes in this regard "The main signpost that helps political realism to find its way through the landscape of international politics…" (Morgenthau 2006: 5). It helps to comprehend the power relations on the international scene and respond to them adequately. It serves as a guideline for the rational foreign policy able to distinguish between interests which are fundamental for a state's survival and secondary ones which could be a subject of political bargains. Finally, it helps to make this policy free from political illusions and ideological mirages (Morgenthau 1952: 972-977;Scheuerman 2009: 76-79, 84).
Nevertheless, the Morgenthau's reference to the universal "laws of politics", and the rationality of political action they imply, is full of tensions and ambiguities. Morgenthau strives to identify some general rules of political activity but at the same time accepts a comprehensive, variable and context-oriented nature of politics itself and a variety of domestic-level variables which may affect the ultimate form of a state's foreign policy. His theory reveals, as Rosenthal underlines, some obvious tensions "…between universality and contingency, between the existence of objective laws and the principle of uncertainty…" (Rosenthal 1991: 7). They reduce the expectations of a state's rational policy which carefully follows the "laws of politics" and the principle of the national interest.
In fact, Morgenthau accepts that a state's foreign policy is determined by a broad catalog of determinants at all levels of analysis (international, unit, and individual) (Morgenthau 1948: 3-7, 96-108). He indicates the existence of the "universal laws" of politics but strongly emphasizes a role (agency) of leadership as well as a social and historical context in which this politics is formulated. Morgenthau agrees that political leaders act in the frames created by the (universal) struggle for power. Yet, he emphasizes leaders' prudence and responsibility (Morgenthau 1947: 145-146;188;Molloy 2008: 92-94). He claims that the struggle for power is not deterministic since wisdom, knowledge, and moderation of the responsible leadership help to tame and master the conflictual nature of politics (Lebow 2008: 28-31;Williams 2005: 169-174). This openness to the quality of leaders, however, becomes problematic for the rationality of a state's foreign policy. The emphasis on the leadership's agency means the acceptance for a variety of mistakes, misperceptions, and miscalculations in leaders' political decisions as well as a game of domestic forces which may accompany foreign policymaking. It suggests that a state's foreign policy may not be as rational as the respect for the universal "laws of politics" implies.
In the same vein, to act rationally in international relations means to follow the guidelines of the national interest (Donnelly 2000: 45). Yet, this rationality is limited again by the variable nature of the interest itself. Morgenthau tends to consider it as "universally valid" but does not reduce the national interest to any specific content and "… does not endow that concept with a meaning that is fixed once and for all" (Morgenthau 2006: 10;Williams 2005: 107-108). The aims of a state's foreign policy may, therefore, change according to a specific time and place in which the state acts (Scheuerman 2009: 82-83, 105-106;Rosenthal 1991: 9). It means that "…the kind of interest determining political action in a particular period of history depends upon the political and cultural context within which foreign policy is formulated" (Morgenthau 2006: 11). Besides, rationality of a state's foreign policy may be reduced in Morgenthau's theoretical considerations by his variable, dynamic, and complex understanding of power (Neacsu 2009: 120). Power in his theory becomes more "a psychological relation between those who exercise it and those over whom it is exercised…" (Morgenthau 1948: 14) and Morgenthau accepts that some of its less tangible components (including diplomacy) may affect the final form of a state's foreign policy (Morgenthau 1948: 96-108;Williams 2005: 109-110). This suggests that rationality may be less a reflection of the "laws of politics" and more a competence of a state's government and its diplomatic service.
Finally, politics remains hardly predictable in Morgenthau's theoretical considerations and "The best the scholar can do, then, is to trace the different tendencies which, as potentialities, are inherent in a certain international situation" (Morgenthau 1948: 6;Gaddis 1992Gaddis /1993. This unpredictable nature of politics reduces rationality impulses from the "universal laws" of politics and distances Morgenthau's theory from more rigorous empirical studies in social sciences (Buzan 1996: 54;Molloy 2006: 75-81). Politics becomes for him "…an art and not a science, and what is required for its mastery is not the rationality of the engineer but the wisdom and the moral strength of the statesman" (Morgenthau 1947: 16). This is a clear reference to the agency of leaders and the quality of a state's leadership again.
Thus, the search for the universal "laws of politics" in Morgenthau's rendition of realism introduces some rationality and predictability to a state's foreign policy. Understanding these "laws" and following the national interest make this policy rational and effective. Yet, the rationality of political action is ambiguous in Morgenthau's considerations. It is reduced by his emphasis on variable, dynamic and context-oriented nature of politics, comprehensive concept of power as well as the strong emphasis on the role (agency) of political leaders. The variables at the unit and individual levels introduce further uncertainty to a state's foreign activity and escape the logic of rationality (Gaddis 1992(Gaddis /1993Donnelly 2000: 48-49). The principle of the struggle for power creates general (but often abstract) frames of international affairs (Gaddis 1992(Gaddis /1993Gilpin 1984: 292), yet they are not deterministic enough to predetermine the final form of a state's foreign policy. The personal features of its leaders or the game of domestic interests may affect the rationality of this policy significantly.

Rationality of International Politics in Waltz's Structural Theory
Kenneth N. Waltz's structural theory of realism, developed at the end of the 1970s, reflected some inspirations from the "behavioral revolution" in the methodology of social science and the systemic attitude to international relations. The former called for a more "scientific" and rigorous methodology (Vasquez 2004: 40-41), while the latter considered international relations as a specific system and aimed at identifying forces which determine its operation and stability (Gaddis 1992(Gaddis /1993Freyberg-Inan et al. 2009a: 3-4).
Hence, Waltz's structural rendition of realism looked for a more rigorous, verifiable and systemic approach-able to identify some recurrent patterns of states' behavior in the international system (Keohane 1986: 168;Taliaferro et al. 2009: 16-17). Waltz was uninterested in the quality of leadership and bracketed any variables at the unit and individual levels (Waltz 1979: 39-41, 98-99;Jones 2009: 231). He focused on states' self-help policy in the anarchic international environment and a distribution of power in the international system which informed about a state's place in the hierarchy of power, a number of most powerful units (polarity) and possible models of states' interactions in the system (Waltz 1979: 88, 93-104;Walt 1998: 31-32). He argued that a state's place in the system affects the final form of its foreign policy since systemic forces may constraint political ambitions inadequate to the state's capabilities (Waltz 1979: 73-75, 107-111;Keohane 1986: 166-167). In line with Waltz, "The structure of a system changes with changes in the distribution of capabilities across the system's units. And changes in structure change expectations about how the units of the system will behave and about the outcomes their interactions will produce" (Waltz 1979: 97).
As a result, the Waltz's systemic approach affected his attitude to rationality of a state's foreign policy. The principal assumption in this regard is that a state's place in the system imposes some constraints on its foreign activity. It favors a policy adequate to a state's power and may impede the policy that exceeds the state's capabilities (Waltz 1979: 73-75, 107-111). In Waltz's words, "The structure of a system acts as a constraining and disposing force" and "…designates a set of constraining conditions" (Waltz 1979: 69, 73-74). The systemic frames (the systemic forces) may limit a state's international behavior and correct its foreign policy's ambitions. They may ultimately bring this policy in line with a state's actual power (Taliaferro et al. 2009: 17-18). It also means that knowing a state's place in the international system helps to identify the type and possible aims of its foreign activity. All units may strive for a variety of particular interests, yet effectiveness of their efforts depends on their place in the system and their actual capabilities (Freyberg-Inan 2004: 74;Keohane 1986: 165). To be sure, Waltz maintains that the behavior of states is still "indeterminate" (Gaddis 1992(Gaddis /1993Little 2009: 28). This suggests that states may ultimately act against the systemic forces. Yet, he warns that such a policy may be "punished" since the structure of the system affects policy of its units "rewarding some behaviors and punishing others" (Waltz 1979: 73-74).
Thus, to act rationally in international relations means to respect constraints and incentives coming from the (structure) of the international system. No reference to leaders and their quality is necessary in this regard. The operation of systemic forces and a state's response, adequate to its power and place in the hierarchy of power, introduce a sense of rationality to its foreign policy-irrespective of social, cultural or historical determinants (Neacsu 2009: 158-159;Jones 2009: 231). Consequently, Waltz's structural logic suggests that states will rationally adapt to their place in the system and recognize systemic determinants of their foreign policy (Wohlforth 1994(Wohlforth /1995Fernandes 1991: 44-47). They will properly asses their capabilities, understand limitations imposed by the system and avoid a policy that could exceed their power and, thus, impede their existence and survival in the system (Taliaferro et al. 2009: 1-2, 17-18;Keohane 1986: 167). Waltz does not claim that states always read the systemic impulses properly or that systemic imperatives will determine their foreign policy absolutely (Gilpin 1984: 301-302;Schweller 2003: 324). States may still decide to act against the systemic forces (Gaddis 1992(Gaddis /1993). Yet, again, they must be aware of consequences of the policy that is irrational-the one which ignores a state's place in the system and its actual material capabilities. Hence, they (rationally) tend to respect the systemic constraints and impulses. This translates into Waltz's claims about regularities of states' rational behavior in the system and "…leads one to expect that the outcomes produced by interacting units will fall within specified ranges". This predicts "continuity within a system" as well (Waltz 1979: 68-69).
In my view, Waltz's systemic perspective assumes more rationality of international relations than Morgenthau's universal (and abstract) "laws of politics". Both theories introduce some rationality and universality to the realist analysis of international processes, yet it seems deeper and more obvious in Waltz's structural considerations (Buzan 1996: 53;Herrmann and Lebow 2004: 14-15). The impact of systemic constraints may not be entirely deterministic and they may affect a state's foreign policy "…primarily through the processes of socialization and competition" (Schweller and Wohlforth 2000: 70). Yet, Waltz still expects that states will rationally adapt to their place in the system and recognize systemic frames of their foreign policy (Wohlforth 1994(Wohlforth /1995Fernandes 1991: 44-47). In the same vein, the systemic attitude of Waltz introduces more predictability of a state's foreign policy than Morgenthau's considerations. The impact of systemic forces reduces ambiguities around the leaders' decisions or the influence of domestic interests on a state's foreign activity. It is more decisive than the "laws of politics" in Morgenthau's theory. The unit and personal level variables, including the nature of states itself, are of secondary importance for Waltz-especially if confronted with strong structural limitations (Taliaferro et al. 2009: 1-2).
Nevertheless, Waltz's systemic theory suffered exaggerated parsimony of its assumptions-based on a few general claims about the structure of the international system and its impact on a state's foreign policy (Lebow 1994: 253;Taliaferro et al. 2009: 16-17). It was static and unable to identify sources of change in the system, especially those rooted in domestic factors (Jones 2009: 226;Wohlforth 1994Wohlforth /1995. The dynamic international processes at the end of the 1980s illustrated the rigidity of Waltz's structural considerations, even for some scholars in the realist camp (James 1993: 133). His purely systemic perspective became "ill-prepared" to comprehend domestic changes in the Soviet Union and their consequences for the final fall of the bipolar system (Wohlforth 1994(Wohlforth /1995James 1993: 132).
The collapse of the bipolar order verified some of Waltz's theoretical claims negatively even if, as Schweller and Wohlforth indicate, it was "…an equally poor fit for all theories that aspire to generalization, whether they are of the structural-systemic, domestic politics, or decision-making variety" (Schweller and Wohlforth 2000: 65). The fall of the Soviet state was complex and dynamic-determined by a variety of causes and difficult to enclose in tight systemic frames (Herrmann and Lebow 2004: 14;Lebow 1994: 251-253). It escaped the schemes of states' rational policy in the international system and expectations of states' rational adaptation to constraints imposed by the system. Finally, it confirmed the role played by political leaders, including Mikhail Gorbachev and his perception of the Soviet decline (Wohlforth 1994(Wohlforth /1995. It would be difficult (even for realists) to deny that Gorbachev's perestroika and his political decisions at the end of the 1980s were full of ambiguities, uncertainty and even improvisation (Snyder 2011: 563-569).

Rationality of Systemic Change in the Hegemonic Rivalry Perspective
The hegemonic rivalry theories, including Robert Gilpin's theory of hegemonic war, remain a systemic attitude which considers international relations in the context of the international system. Nevertheless, they pay more attention to a (hegemonic) change in the system and a variety of sources which determine rise and fall of a state's power. The hegemonic rivalry approach focuses on cyclical changes of system's leaders. It considers international relations to be long cycles of the rise and fall of hegemonic powers, and identifies a variety of causes behind the hegemonic change (Gaddis 1992(Gaddis /1993. The process of power transition recurs as hegemons face rising challengers and finally lose their domination in the systems (Schweller and Wohlforth 2000: 76). It makes international relations "an unending series of cycles" (Keohane 1986: 177) and, in line with Gilpin, "The conclusion of one hegemonic war is the beginning of another cycle of growth, expansion, and eventual decline" (Gilpin 1981: 210). As a result, the international system remains stable as long as the power preponderance of a system's leader remains unquestioned (Wohlforth et al. 2007: 20). The leader (hegemon) introduces rules, norms and institutions that reflect its interests and regulates the system's operation (Lemke 1997: 24;Schweller and Wohlforth 2000: 78). Yet, the uneven growth of power in the system may weaken and ultimately challenge the leader's position. In Gilpin's words, "In time, the differential growth in power of the various states in the system causes a fundamental redistribution of power in the system…" and "…those actors who benefit most from a change in the social system and who gain the power to effect such change will seek to alter the system in ways that favor their interests" (Gilpin 1981: 9, 13). The rise of the second state in the hierarchy of power (the challenger) becomes crucial in this regard, especially if the dynamic increase in its power and a simultaneous drop in the capabilities of the leader boost the challenger political aspirations (Wohlforth et al. 2007: 12). The clash of their interests undermines stability of the system, increases their hegemonic rivalry and leads to the hegemonic confrontation when the power of the challenger reaches the power of the hegemon (Gilpin 1988: 595-605;Wohlforth et al. 2007: 12). The new leader who emerges from this confrontation introduces his own rules in the international system and his victory begins a new hegemonic cycle (Gaddis 1992(Gaddis /1993. Thus, the most obvious and rational in the policy of the existing hegemon would be to prevent the rise of the challenger's power. This rationality, however, is reduced in the hegemonic rivalry perspective by the hegemonic position itself. The hegemon sets the rules of the international system but usually pays high costs for managing the system and providing a variety of "systemic services" which other states consume without sharing their costs. It may weaken its own domination with a tendency to "consume more and invest less", exhaustion and bureaucratization (Keohane 1986: 179;Gaddis 1992Gaddis /1993. Finally, the hegemon may engage in costly and counterproductive interventions to ensure that its hegemonic rules are obeyed. They may contribute to the hegemon's "overextension" and costs of its domination that exceed potential benefits (Wohlforth et al. 2007: 20). All this suggests that a hegemon's preponderance of power does not automatically translate into rationality of its foreign policy.
Further, the law of uneven growth of power in the hegemonic perspective is less deterministic than Waltz's structural determinants of a state's foreign policy. Gilpin and other theorists in the hegemonic rivalry stream indicate a variety of factors which may cause dynamic shifts in the hierarchy of power in the international system. They refer to economic and technological determinants but (in the case of Gilpin) tend to accept that even some unit-level variables may affect the final form of a state's foreign policy. In Gilpin's words, "Both the structure of the international system and the domestic conditions of societies are primary determinants of foreign policy" (Gilpin 1981: 87) and it may be the nature of a state's social, political and economic institutions or some attributes of its leaders which ultimately contribute to the rise or decline of its power (Gilpin 1981: 30-32, 87;Wohlforth 2011: 503-509). Hence, it is rational for a hegemon to properly identify the sources of change in the international system, and the sources of growth of its own power, as missing the opportunity to adapt to new processes may result in its decline and loss of its hegemonic position (Gilpin 1988: 597-599, 603-605). Yet, for the hegemonic rivalry stream of realism, such rational calculation is not a foregone conclusion and the existing hegemon may simply overlook the sources of change in the system (Lemke 1997: 24).
Consequently, it might look rational that a weakening hegemon opts for a preemptive strike as long as its power still gives it a chance to defeat the rising and ambitious challenger (Gilpin 1988: 595-605;Wohlforth et al. 2007: 12). Yet, in line with Gilpin's considerations, it may equally be rational to apply the strategy of retrenchment which involves reducing costs of the hegemon's international position and slowing down its decline (Gilpin 1981: 115, 192-194). It may be rational to abandon some peripheral but costly commitments or ally with less threatening powers in the system. Finally, it may even be reasonable (although riskier) to try to offer some concessions to the challenger "to seek to appease its ambitions" (Gilpin 1981: 192-194). Such retrenchment is difficult, "uncertain" and depends "on timing and circumstances" (Gilpin 1981: 192). Yet, it may (rationally) help the hegemon to keep the system under its own rules with some shifts necessary to respect the ambitions of the challenger (Schweller and Wohlforth 2000: 80-81).
Thus, the hegemonic rivalry theories remain a systemic attitude which identifies a general model of the hegemonic change in the international system. It introduces rationality and predictability to the foreign policy of both hegemons and rising challengers. Yet, the rise and fall logic in the hegemonic perspective is more nuanced and less deterministic than the impact of systemic forces in the Waltz's structural considerations. To act rationally in the international system a state needs not only to understand consequences of its place in the hierarchy of power. It needs an ability to properly identify sources of potential changes in the system and determinants of a rise (or decline) of its own capabilities. Besides, for Gilpin, the international system is less stable and more variable than in the structural theory of Waltz, especially during the periods of hegemonic decline. The shift in the hierarchy of power may be dynamic and even most powerful units should "…think of any international system as temporary, and to look for the underlying causes of change, which accumulate slowly but are realized in rare, concentrated bursts" (Wohlforth 1994(Wohlforth /1995.
In fact, the hegemonic rivalry perspective takes the "middle ground" between a purely structural and systemic perspective of Waltz and considerations of Morgenthau. It accepts systemic and rational frames of a state's foreign policy but, unlike Waltz, reaches for some domestic determinants of a state's power and looks for a variety of sources which cause systemic change. Hence, the hegemonic perspective will expect more rationality of a state's foreign policy and more respect for systemic constraints than Morgenthau but is certainly much less static and rigid than the attitude of Waltz.

Rationality of International Processes in Post-Cold War Realist Theories
The evolution of the realist paradigm during the Cold War revealed a difference of realist views on rationality of international relations, as the comparison of Morgenthau's and Waltz's theoretical considerations illustrated. The Cold War period made the Waltz's systemic and structural perspective more applicable since the logic of the bipolar rivalry reduced the impact of domestic variables on great powers' foreign policy. The bipolar confrontation required more verifiable, rational, and predictable schemes of international processes and Morgenthau's considerations about leaders' prudence and responsibility (even if valuable and inspiring) could not be of the principal importance for a strategic analysis. The Waltz's perspective, based on some general patterns of a state's international behavior, adequate to its power and place in the international system, could potentially introduce more rationality and predictability to this analysis (Wohlforth 2011: 501-502). Yet, as the hegemonic rivalry theories warned, the structural perspective could be too narrow to understand the sources of change in the international system and the international processes could be difficult to picture without at least some references to unit-level determinants. Similarly, the expected rationality of a state's response to systemic constraints could in practice be affected by its leaders' perceptions (or misperceptions). Finally, the fall of the Soviet state in the late 1980s proved that the purely systemic perspective alone could say nothing about the dynamics of international affairs in the periods of "revolutionary change" (Wohlforth 1994(Wohlforth /1995. The reality of post-Cold War international relations reduces the role of the systemic perspective even further. It makes a departure from the model of rationality based on some general schemes of international behavior-in response to a state's place in the international system-inevitable. The place in the system (which reflects a state's power) still affects a state's foreign policy. Yet, a dynamic and complex nature of contemporary international relations, as well as a number of factors which reduce the struggle for power (global economic processes, regional integration), requires a more nuanced attitude which goes beyond the expectations of states' rational adaptation to systemic and structural determinants of their foreign activity. It translates into a reach for a variety of unit-level variables (domestic and individual). Further, it introduces much wider contextual and relational aspects of international processes which, in some theoretical perspectives, become "the basic ontological condition of international actors" (Kavalski 2018: 235, 241). Contemporary realists tend to accept that it becomes difficult and counterproductive to enclose international relations in some systemic frames of analysis (Rose 1998: 167-168), yet the debate inside realism on the nature and rationality of contemporary international processes is far from conclusion. It affects considerations of elaborated structural realism and neoclassical realism, two leading post-Cold War streams of realism, and their views on rationality of political action.
Elaborated structural realism aims at retaining the systemic logic of analysis but reaches beyond the distribution of power in the international system as the main variable. It indicates a variety of other systemic factors, different than the hierarchy of power, which could enrich the systemic perspective and make it less rigid (James 1993: 131-136, 140-141;Freyberg-Inan et al. 2009b: 255). It offers a wider and more flexible systemic attitude than Waltz's structural theory. It refers to some geographical variables, including a state's regional political environment (James 1993: 140;Mearsheimer 2001: 40-42), the concentration of power in the system as well as changes of power relations in different regional contexts. Further, the elaborated structural perspective refers to a variety of states' interactions in the system-with alliances as the most obvious "products of interstate interactions" (James 1993: 135-140;Freyberg-Inan et al. 2009a: 4-7). Finally, and in opposition to Waltz, it accepts that even some motivational aspects of states' relations in the system, including their ambitions and fears, may have some systemic consequences (James 1993(James : 135-138, 2009).
Yet, the elaborated structural approach is cautious in its reference to motivational context of international processes (James 2009: 45) and declares that any motivational variables it considers must retain their systemic consequences (James 1993: 139-140;Freyberg-Inan et al. 2009b: 255). It is reluctant to cross the level of the international system to absorb some domestic aspects of foreign policymaking and warns about uncontrolled proliferation of variables (James 1993(James : 140, 2009. The aim of elaborated structural realism is, therefore, to make the initial Waltz's theory less rigid, yet it still appreciates a theoretical unity of the systemic approach and aspires to formulate a consistent systemic perspective of international relations which keeps some "…parsimony and elegance associated with structural models" (Freyberg-Inan et al. 2009a: 4-5).
Hence, the elaborated structural realist attitude to rationality of international processes reflects ambiguities which the systemic approach faces in the dynamic and complex reality of post-Cold War international relations. Elaborated structural realism intends to retain some certainty and predictability that a state's rational adaptation to structural determinants of its foreign policy entails. It introduces a more flexible systemic perspective of contemporary international processes, yet still favors consistency and unity of the systemic analysis which could place a state's foreign activity in some rational and predictable frames (James 1993(James : 142, 2009. It introduces a broader catalog of systemic variables and reluctantly refers to political motivations and intentions but it could engage in a new debate on recurring patterns of a state's rational behavior (adequate to its capabilities and place in the hierarchy of power) even in the post-Cold War international system. Yet, in my view, the problem with the systemic and structural approach is that in international relations at the beginning of the twenty-first century, it may offer very general frames of a state's foreign activity-too general to build a new theory on them. It may offer a vague "systemic rationality" that may considerably be modified by a variety of unit-level variables. The systemic perspective may still potentially be useful when analyzing some structural and rational aspects of states' foreign policy, and especially the policy of great powers. Yet, even in the case of the United States, the political interpretations and concepts of subsequent presidential administrations may affect the structural and systemic frames of the US foreign activity (Freyberg-Inan et al. 2009b: 255-256). Further, it was paradoxically Waltz who emphasized after the fall of the bipolar order that "In the absence of counterweights, a country's internal impulses prevail, whether fueled by liberal or by other urges" (Waltz 2000: 24). Thus, the model of a state's rational response to structural determinants of its foreign policy may be difficult to apply in contemporary international relations. It may be too general and parsimonious (if not misleading) if not accompanied by a broader reference to domestic nuances of foreign policymaking.
The neoclassical stream of realism goes much further in its openness to unitand individual-level variables. It agrees that systemic determinants frame a state's foreign policy which is still "…driven first and foremost by its place in the international system and specifically by its relative material power capabilities" (Rose 1998: 146-147;Taliaferro et al. 2009: 5, 27-28). Yet, it underlines that the impact of systemic constraints is indirect in contemporary international relations and "must be translated through intervening variables at the unit level" (Rose 1998: 146). In a short or medium term, a state's response to systemic determinants may be ambiguous and systemic forces will certainly not explain all nuances of its foreign activity (Taliaferro 2000(Taliaferro /2001Sterling-Folker 2009: 208-209). Hence, the pressure of the system is less decisive in the neoclassical realist perspective than in elaborated structural realism and far less deterministic than in the structural theory of Waltz (Taliaferro et al. 2009: 28). To shape a state's foreign policy, systemic impulses are "filtered" and "transmitted" through a variety of domestic factors. This transmission, however, may be complex and states may not always read the systemic signals properly (Rose 1998: 146-147;Taliaferro et al. 2009: 4).
As a result, to study post-Cold War international relations, neoclassical realism reaches for a variety of unit-and individual-level variables. In a sense, it derives some inspirations from Morgenthau's previous theoretical considerations (Donnelly 2005: 40;Mouritzen 2009: 165). Neoclassical realism returns to political leaders, their perception of power and the impact of this perception on a state's foreign policy (Rose 1998: 146-147;Taliaferro et al. 2009: 5, 28). Yet, this perception may dynamically evolve in the neoclassical realist perspective. It may contribute to some inconsistencies in a state's foreign activity and different understanding of systemic constraints by different states, even those of comparable material power (Schweller 2003: 338-339;Rose 1998: 146-147). Further, neoclassical realism refers to a variety of domestic social, political, and economic forces (Taliaferro et al. 2009: 4). It indicates that a state's actual foreign policy may be a result of elites' bargain with domestic interest groups or leaders' ability to mobilize social support for their political aims (Rose 1998: 161-163;Taliaferro et al. 2009: 25-26). Finally, it considers a state's nature itself, its political regime and even values shared by its society which may ultimately affect a state's answer to systemic frames of its foreign policy (Schweller 2003: 337;Devlen and Özdamar 2009: 142-143).
Thus, in the context of rationality of political action, neoclassical realism suggests that a state's response to systemic constraints may be ambiguous-far more than in the elaborated structural perspective. Much wider reference to domestic determinants of a state's foreign policy, including the perception of power, opens more space to irrationality, inconsistency, and misperceptions in this policy (Taliaferro et al. 2009: 7-8, 29-30;Schweller 2003: 336-337). It potentially makes a state's answer to systemic frames indirect, vague, and far from a single and optimal choice. The international system may still "shape the broad contours" of a state's foreign policy but it hardly determines "the specific details of state behavior" (Rose 1998: 146-147).
Consequently, neoclassical realism brings, in line with Balkan Devlen and Özgür Özdamar, "the statesman back in" (Devlen and Özdamar 2009: 138). It offers a complex analysis of forces behind a state's foreign policy-closer to Morgenthau's context-oriented approach than structural realist perspective (Taliaferro et al. 2009: 7;Rose 1998: 153-154, 165-168). It clearly departs from the Waltz's picture of states as unitary and rational units in the international system able to smoothly read and respond to systemic impulses (James 1993: 125-126;Schweller 2003: 334). Their final foreign policy, affected by a variety of domestic determinants, may not be a rational, consistent, and optimal political choice-most adequate to systemic frames (Rose 1998: 146, 158;Sterling-Folker 2009: 209). Besides, in the complex reality of post-Cold War international relations, it may be difficult for states to identify which strategy is optimal and which response becomes appropriate and rational (Ripsman et al. 2009: 288-289).
Hence, the openness to unit-level variables helps neoclassical realism to comprehend the nuances of contemporary international processes. Yet, the neoclassical realist perspective faces challenges similar to those faced previously by Morgenthaupotential irrationality and inconsistency in a state's foreign policy together with its emphasis on the "modifying" role played by leaders, elites, and domestic structures. Neoclassical realism tries to accommodate potential mistakes, misperceptions and miscalculations in a state's foreign policy and integrate them with some general and rational systemic frames. The impact of the latter becomes indirect and modified by a domestic context but they still (at least in the longer term) help to expect some rationality, continuity, and predictability of this policy. This attitude, however, provokes tensions and inconsistencies, since it is still unclear which impulses (systemic or domestic) prevail.
Finally, neoclassical realism risks that the abundance of variables, at different levels of analysis, may reduce its ability to offer any general conclusions about contemporary international processes (Taliaferro et al. 2009: 16-19). Its further interest in domestic nuances of foreign policymaking provokes doubts about neoclassical realism's ability to retain any parsimony of its theoretical considerations and warns about it turning into a "loose collection of case studies"-far from any rationality and predictability (Rose 1998: 167-170;Donnelly 2005: 74-75).

Considering Rationality of Contemporary International Relations-Challenges and Dilemmas for Realism
The differences between the elaborated structural realist and neoclassical realist assumptions illustrate a number of dilemmas which realism faces after the end of the Cold War and which may affect its attitude to rationality of contemporary international relations. Theories of international relations, including realism itself, are faced with a more complex nature of contemporary international processes, difficult to be enclosed in some structural (systemic) frames of analysis. It makes state's political choices more nuanced and shaped by a wider catalog of determinants than its place in the hierarchy of power. It means the acceptance that some domestic variables, including leaders and their perceptions, will modify previous systemic and structural considerations. The scope of this modification may be disputable, yet the post-Cold War reality introduces more ambiguity into international relations and more space for "individual, group, and cultural variation" (Herrmann and Lebow 2004: 8-9, 18;Kavalski 2018: 235). It means that, in line with Herrmann and Lebow, "some phenomena may be explained by single causes", yet others "have multiple causes that must be taken into account" to explain them (Herrmann and Lebow 2004: 14). Nevertheless, it means that the growing number of variables and determinants behind a state's foreign policy reduces the previous structural realist expectations of rationality of this policy-understood as the calculation of costs and benefits, evaluation of systemic constraints and choosing political strategy optimal to implement state interests. This rational-actor model has been a subject of controversies much earlier, including some criticism from the psychological, cognitive or bureaucratic perspectives (Vasquez 2004: 156-160). Yet, the post-Cold War reality introduces many more aspects of uncertainty, inconsistency and misperception to the analysis of international relations than any realist considerations during the Cold War period. This confronts realism with a fundamental question of how parsimonious, general and rational theories may actually be in the international reality at the beginning of the twenty-first century (Taliaferro et al. 2009: 17-18;Freyberg-Inan et al. 2009a: 10-11). Realism agrees that the experience of the fall of the Soviet Union and the complex nature of post-Cold War international processes make the departure from the Waltz's systemic perspective unavoidable. They reduce the coherence and rationality of structural realist considerations as well (James 2009: 47-48;Wohlforth 1994Wohlforth /1995). Yet, realism still faces tensions between a complexity of contemporary international affairs and a tendency to enclose them in some general theoretical frames, to include some patterns of a state's rational response to systemic determinants of its foreign policy (Freyberg-Inan et al. 2009a: 3-4).
Realism accepts that no one of its streams will be able to offer a single, rigorous and general perspective of international processes (Donnelly 2000: 107, 194-195). No one would probably expect rationality of states' response to systemic constraints similar to that in the Cold War period. In the same vein, realism (and especially its neoclassical stream) tends to accept that understanding contemporary international affairs needs a bolder reference to domestic determinants of a state's foreign policy. It may require a context-oriented theoretical perspective and a more comprehensive picture of social, historical, and political aspects of this policy (Schweller 2003: 321-322;Taliaferro et al. 2009: 7). Yet, in line with Waltz, "including more" does not always mean "explaining more", especially if new variables lose internal consistency of the previous theoretical considerations (Waltz 2004: 2-4;Waever 2011: 78). Hence, realism still appreciates a theoretical unity, consistency, and rationality of the systemic approach. The state's place in the international system still determines its foreign policy and affects its rational activity on the international scene since "Even the most revolutionary state would not revolutionize world politics if systemic influences resisted that objective…" (Gaddis 1992(Gaddis /1993. Contemporary realism still needs some general conclusions about international relations since without such generalizations "…there is no obvious path towards coherent theory" (Buzan 1996: 54-55).
Therefore, even neoclassical realism tries to offer some general conclusions about causal importance of domestic variables and the way in which domestic interest groups affect a state's foreign policy (Taliaferro et al. 2009: 37). It indicates, in line with Ripsman, Taliaferro and Lobell, that the role of domestic forces may differ according to clarity of systemic constraints as well as information which the system "provides on how best to respond to these structural conditions" (Ripsman et al. 2009: 282). If the constraints imposed by the system are unambiguous and the system provides "clear information on how to respond to them" the role of domestic variables may affect rather the style and timing of a state's foreign policy and not its essence (Ripsman et al. 2009: 282-287). This clarity helps to expect a policy that rationally calculates a state's interests as well. Yet, even the clear signals sent by the international system do not prevent, in the neoclassical realist perspective, some leaders' misperceptions and miscalculations (Ripsman et al. 2009: 282-284). They still modify any assumptions about a state's rational response to systemic constraints.
Thus, realism faces a dilemma of whether to keep the parsimony of the structural perspective but miss the nuances of contemporary international processes, or favor openness to a variety of non-systemic variables, but risk its ability to offer a more general picture of international affairs (Legro and Moravcsik 1999: 6;Ripsman et al. 2009: 298-299). Realism is still far from a consensus in this regard and a common understanding of what rationality of a state's foreign policy means in contemporary international relations. In my view, the acceptance of some elements of misperceptions, miscalculations, and unpredictability becomes inevitable and neoclassical realism is in a better position to offer a new realist explanation of international processes. Yet, it must first answer a question of how far to reach for domestic variables (Herrmann 1997: 13-14;Harrison 2009: 84-85). It needs to address the fundamental problem of how deep to delve into domestic nuances of foreign policymaking and how much to "understand about actors and their perspectives" (Freyberg-Inan et al. 2009a: 9;Herrmann 1997: 13-14). In other words, it must identify a border beyond which realism loses any theoretical unity, rationality, and predictive abilities (Harrison 2009: 92-99;Freyberg-Inan et al. 2009a: 6).
Further, the principal challenge for the neoclassical stream of realism (and the realist paradigm in general) is how to integrate the aspects of uncertainty into the new theoretical perspective. Realism needs to retain some of its assumptions about the international system and its impact on a state's foreign policy and about a state's ability to rationally respond to systemic impulses. Yet, it needs to propose a new approach that would accommodate agency of political leaders or nature of states themselves. It is a challenge to respond to a variety of determinants behind contemporary international processes (Gaddis 1992(Gaddis /1993Herrmann and Lebow 2004: 6-9). Finally, it is, in line with John L. Gaddis, a more general problem of social sciences that, seeking objectivity, reached for traditional methods of natural science but did so at the moment when natural sciences "were abandoning old methods in favor of new ones that accommodated indeterminacy, irregularity, and unpredictability-precisely the qualities the social sciences were trying to leave behind" (Gaddis 1992(Gaddis /1993. Neoclassical realism responds to these challenges by its declaration of a creative synthesis of structural (systemic) and domestic determinants of a state's foreign policy. It emphasizes the primacy of material aspects of contemporary international processes but repeats its acceptance for a variety of (less verifiable) intervening variables at the unit level. They "filter" and modify impulses from the international system (Taliaferro et al. 2009: 4-5, 13-22;Schweller 2003: 336-337). Yet, in my view, the actual role of domestic variables is still unclear in the neoclassical realist perspective and the combination of the levels of analysis will always, in line with Guzzini, provoke a question of where the logical priority is assigned (Guzzini 1998: 196-197). Further, and despite the problem of the causal priority, it is still difficult to determine the extent to which domestic processes may and should modify systemic constraints of a state's foreign policy and affect its rationality. In an extreme interpretation, states may rationally calculate their opportunities according to their power and place in the international system yet, after the intervention of non-systemic variables, the final form of this policy may considerably differ from the original interests. Thus, in line with Henry Nau, while "in a sense everything is up for grabs" not everything "works in terms of outcomes" (Nau 2011: 463-464).
Besides, realism may not be in a position to propose a new and creative synthesis of systemic and domestic aspects of contemporary international processes. It still offers some valuable power considerations which are crucial for any debates on rationality of a state's foreign policy. Yet, over the past several decades, it has lacked a consistent perspective able to integrate its power considerations and some elements of norms, laws, and rules of international society-something that the English School offers in a more coherent way. Some Morgenthau's conclusions about the mechanisms to reduce the struggle for power or the hegemonic rivalry theories' sensitivity to a variety of sources behind a state's power remain valuable. This sensitivity returns in the neoclassical realist considerations but the neoclassical realist understanding of contemporary international relations is still far from an integrated and mature perspective.
Scholars differ in their views on rationality of realism. In line with Schweller and Wohlforth, "Although some realist theories make strong assumptions about rationality, such assumptions are not essential to realism" (Schweller and Wohlforth 2000: 70). On the other hand, as Devlen and Özdamar indicate, "there is nothing inherent" in contemporary realism, including its neoclassical stream, that "would forbid" rationality of its assumptions (Devlen and Özdamar 2009: 158-159). In my view, the complexity of contemporary international relations makes a state's capability to rationally respond to systemic frames of its foreign policy problematic. Realism needs a new picture of a state's rational behavior in the international environment at the beginning of the twenty-first century. Yet, its ability to offer a synthesis of domestic and systemic aspects of contemporary international processes is still limited.

Conclusion
Realism has never been unified in its view on rationality of international relations as different perspectives of Morgenthau and Waltz illustrate. The bipolar confrontation during the Cold War period contributed to Waltz's general schemes of a state's rational foreign policy-in response to systemic constraints and its place in the international system. Yet for other realists, including hegemonic rivalry theories, the purely systemic attitude was too static and rigid. The fall of the bipolar order makes contemporary international processes more dynamic and complex-difficult to enclose in some systemic and rational schemes (Rose 1998: 167-168). Contemporary realists agree that to comprehend the post-Cold War international affairs, realism needs to depart from the rigid and parsimonious structural perspective. Most accept that the impact of systemic constraints on a state's foreign policy becomes less deterministic and agree on reaching for some domestic-level variables (unit and personal) (Schweller and Wohlforth 2000: 99;Wohlforth 1994Wohlforth /1995). Yet, they are far from a consensus on how far this departure should be and neoclassical realism delves into domestic determinants of a state's foreign policy much deeper than any elaborated structural stream of realism.
Nevertheless, the disputes inside realism do not change the general picture that the complex nature of post-Cold War international relations reduces the initial Waltz's expectations of rationality of a state's behavior in the international system (Freyberg-Inan et al. 2009a: 6). Contemporary realism departs from the picture of states which appropriately calculate risks and benefits, understand their place in the system and select a policy optimal to structural (systemic) conditions. States may still calculate different options of their foreign policy, yet this calculation becomes more ambiguous and may be modified by domestic nuances of foreign policymaking.
The international reality at the beginning of the twenty-first century results in realism being faced with some challenges and dilemmas. On the one hand, it seeks to retain some general theoretical conclusions and some rational patterns of states' behavior in the international system (Buzan 1996: 54-55). On the other hand, it needs to accommodate the impact of misperceptions, miscalculations or mistakes in leaders' political decisions. Besides, the impulses from the system itself may be unclear and indirect. Realism intends to retain some unity, rationality and coherence of the systemic perspective, yet understands that this perspective is limited in contemporary international relations (Donnelly 2000: 107, 194-195;Taliaferro et al. 2009: 21). It is aware that further absorption of unit and personal level variables will reduce rationality of a state's foreign policy but understands that this absorption becomes inevitable.
The realist response to these challenges is unclear as the debate between neoclassical realism and elaborated structural realism illustrates. Realists agree that contemporary international processes will not be as rational as in the Waltz's structural perspective but disagree how "irrational" they could actually be. The neoclassical realist idea of a creative synthesis, that integrates some aspects of misperceptions and miscalculations in contemporary international relations but retains some "systemic rationality" of a state's foreign policy, may be a way ahead. Yet, it is still ambiguous and needs further elaboration.

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