The term restrainer calls to mind many different images: on one hand, a group of anti-war activists disillusioned by American failures in Iraq and Afghanistan; on the other, a cohort of ivory tower academics with years of experience immersing themselves in the study of international relations. Most restrainers are usually somewhere in between these archetypes. The term restraint is now so entrenched within the realist school that two famous academics, John Ikenberry and Daniel Deudney, rightfully characterized the restrainer movement as a loose coalition of realists, libertarians, and progressive critics of liberal internationalism.  Nowadays, proponents of realism such as John Mearsheimer – an academic who pioneered the offensive realist theory – have begun to synonymize what used to be a purely descriptive theory into a more prescriptive agenda for a more restraint-based U.S. grand strategy, oftentimes leveraging the academic rigor of the theory to lend it authority.  However, realism is not necessarily the precursor to a grand strategy of restraint. Offensive realism is simply a descriptive theory of international relations, and it is compatible with a prescriptive grand strategy of proactive engagement and primacy.
Before discussing what realism, or better yet, offensive realism, should normatively prescribe in U.S. grand strategy, it is important to establish the theory’s governing assumptions. Realism as a theory in international relations has evolved over time, but its assumptions have remained consistent throughout its evolution. The first assumption is that survival is the key goal of a great power, meaning that states will prioritize their existence above all other objectives.  The second assumption is that states are the most important actors in international politics, and that states are rational, unitary actors.  The last and most important assumption is that the international system is anarchic, meaning that there is no central world government that governs the actions of sovereign states within the system.  However, many realists diverge on how states react to international anarchy.
One major divergence in the realist school is the division of defensive and offensive realism, which have contrary beliefs as to how states achieve security for themselves given the phenomenon known as the “security dilemma.” The dilemma goes as follows: if the international system is anarchic, fear and insecurity would dictate a state’s policies, as there is no higher authority in the international system to turn to if attacked. Therefore, a state would inevitably seek more power to prevent itself from being conquered by other states. It would attempt to grow its power by forming alliances and strengthening its military, which would provide the state with new capabilities with which to defend itself. However, such actions, initially intended as defensive in nature, would be perceived as offensive to other states in the system that feel threatened by their counterpart’s increased military capability. The dual-use nature of military capability is the origin of the security dilemma: any action taken by a state to increase its own security risks an arms race with other states, decreasing international stability. 
Within structural realism, there are two approaches to mitigating the security dilemma. On one hand, proponents of defensive realism argue that states should not seek offensive actions and maximization of their power to increase security, as it would induce a counterbalancing reaction from other states. This argument holds that if a state garners too much power within the international system, then it would disrupt the balance of power, which keeps the system stable, thus causing other states to form alliances against the rising power. If this is true, how would a state strike the delicate balance between having enough power to defend itself from being conquered while also not inciting other powers to form alliances against it? Defensive realist Robert Jervis provides one answer, suggesting that simply building defensive technology that cannot be used offensively could signal non-revisionist intentions. 
The other side of the debate, that of the offensive realists, suggests that the distinction between offensive and defensive capabilities either does not exist or is not relevant, as states are always uncertain of other states’ intentions. Even if a state were to exclusively arm itself with defensive weapons systems, this side argues it is entirely possible for that state to leverage those capabilities for offensive purposes. Offensive realists have existed and animated the debate for decades after the advent of structural realism theory, taking the name of “aggressive realism” in Jack Snyder’s Myths of Empire: Domestic Politics and International Ambition.  However, the theory that a state will maximize power to ensure its security was formalized by Mearsheimer in The Tragedy of Great Power Politics, which emphasized the indistinguishability between defensive and offensive capabilities and intentions. 
Offensive realism claims that states will seek out regional hegemony as the primary objective to ensure survival in an anarchic international system. In addition to the three realist assumptions, it operates under two additional assumptions: first, that states are uncertain about other states’ intentions, and second, that every state inherently possesses some sort of offensive capability.  Because states are uncertain of one another’s intentions, the only way to ensure security is to maximize power at any cost, which means achieving regional hegemony in the state’s respective region while also preventing the rise of another great power in another. Mearsheimer called Jervis’s point on the distinguishability between defense and offense “too vague,” suggesting that “it is hard to distinguish defense from offense” in practice.  In turn, as another defensive realist Charles Glaser has pointed out, Mearsheimer implicitly argued that the security dilemma “does not exist or at least that it should never constrain states.”  Given that the dilemma should never constrain states, Mearsheimer’s interpretation of the dilemma serves as one of the defining features of his offensive realist theory.
In the context of U.S. grand strategy, numerous prominent realists have come forward against the notion of American primacy and engagement in world affairs. As an objective, realists in general believe that protecting U.S. national security and promoting American prosperity should serve as the vital national interest for the United States.  Thus it makes sense for defensive realists to advocate for a strategy of restraint: they believe that the more power a state garners, the more likely that other states would coalesce into a balancing alliance against it to preserve the global balance of power. That was the argument laid bare by Eugene Gholz, Daryl Press, and Harvey Sapolsky in “Come Home, America: The Strategy of Restraint in the Face of Temptation,” which popularized the term “restraint” in realist literature. 
Although restraint is originally a defensive realist concept, many offensive realists also advocate for it. Mearsheimer has long argued in favor of restraint, characterizing the current grand strategy as one of “liberal hegemony.” Mearsheimer has consistently argued that liberal hegemony is a grand strategy that is not based on a set of policies grounded in the logic of realism, but instead is motivated by domestic politics and what he believes is the foreign policy establishment’s desire to promote liberal democracy abroad as a means for securing global peace.  Instead of liberal hegemony, Mearsheimer advocates for what he calls “offshore balancing,” a strategy of providing over-the-horizon capabilities to a balancing coalition against a rising power, in what he perceives as the more immediate threat to U.S. national security interest: the threat of China’s hegemony in the Indo-Pacific.  In Mearsheimer’s view, offshore balancing requires reprioritization of force structure in U.S. military presence away from Eu- rope and the Middle East and towards Asia to combat the Chinese threat, which necessitates restraint in the other two theaters.
The realist appeal to restraint is most apparent in the European theater. As international relations scholars Andrey A. Sushentsov and William C. Wohlforth rightfully point out, the U.S.-NATO-Russia spiral divides commentators into two camps.  The first, mostly made up of realists, argues that the United States is a greedy expansionist state that sought out NATO enlargement for non-security reasons, namely liberal internationalist ideology or domestic politics, while Russia is a pure security seeker that takes offensive actions in reaction to NATO enlargement. The second camp, mostly made up of liberal internationalists, argues that Russia is an expansionist state responding to NATO enlargement for non-security, domestic political reasons, while the United States is fundamentally a security seeker attempting to provide stability in Europe by expanding the NATO alliance. But never has it been the case that a realist adopts a third position which is consistent with their own worldview: both the United States and Russia are security seekers and are trapped in a security dilemma.
In promoting restraint in Europe and the Middle East, Mearsheimer has sided with the former camp, leveraging his offensive realist theory to argue that NATO enlargement was a mistake, laying the blame on the West for the Russian invasion of Ukraine and comparing Russian expansionist geopolitical ambitions to that of the United States in its Monroe Doctrine, arguing that it is natural for Russia to seek more power in Eastern Europe.  The logic of the security dilemma would show, he contends, that even if the NATO alliance were to espouse defensive intentions, the uncertain nature of international politics – in which intentions cannot be deciphered by other states – would compel Russia to perceive the enlargement as an offensive action, compelling it to pursue counter-escalatory measures.  He then argues that Russian actions in Ukraine and Georgia are defensive actions in reaction to NATO enlargement, and that Russia would not have chosen its current offensive strategy had the West not first provoked it.
If the actual theory of offensive realism is applied to policy, however, it does not lend much credence to his line of reasoning. For starters, Mearsheimer’s theory of offensive realism asserts that states maximize power and bid for regional hegemony to guarantee their own security in the international system independent of the actions of other states due to the assumption that “states can never be certain about other states’ intentions.”  Given that all states, including Russia, inherently possess “revisionist intentions to maximize power independent of the actions of other states,” it would logically follow that great powers should attempt to balance against any state that is both capable and intending to seek out regional hegemony. This line of reasoning leads to a difficulty: if Russia was a revisionist state with a hegemony-seeking intention or motive, why would Russia abandon its expansionist intentions if its neighboring states were to pursue “non-aggressive” policies?
But more importantly, Mearsheimer hinges his blame of NATO on his interpretation of the security dilemma. He argues that any attempt to maximize power – in this case, enlarging the NATO alliance – is a move that may be intended as a defensive posture but would still be perceived as offensive by the Russian state. Therefore, any action that Russia takes is in response to NATO enlargement, drawing a distinction between Western policies in Europe which are offensive while Russian “responses” to those aggressions are defensive in nature. In other words, Mearsheimer adopts a defensive realist position on the security dilemma to justify his position on NATO enlargement. 
However, the indistinguishability of defensive and offensive capabilities can apply both ways. NATO enlargement being perceived as offensive posturing despite its defensive intention equally applies to the Russian state; the West condemns Russian aggression as ‘offensive,’ while the Russians would call their policies ‘defensive.’
Although an aggressive Russian response may be a predicted outcome given the spiral model, the model hardly provides a prescription of concessionary response to those counter-escalations given the same indistinguishability of defensive or offensive intention of the reacting state’s (in this case, Russia’s) aggressive response. And, in accordance with offensive realism, states should maximize power and capabilities regardless of those intentions due to indistinguishability and misperception. When Mearsheimer claims “the issue at hand is not what Western leaders say NATO’s purpose or intentions are; it is how Moscow sees NATO’s actions,” it equally applies to the contrary: the issue at hand is not what Russian leaders say Moscow’s purpose or intentions are; it is how Washington sees Russia’s actions. 
If one adopts the third view, as any offensive realist should, that both the United States and Russia are security seekers, the right course in Europe would be for the United States to pursue a grand strategy of primacy, which recognizes the indistinguishability of offense and defense as well as uncertainty of other states’ intentions, necessitating a strategy of maximal primacy. This would be applied in Europe through NATO enlargement, a strategy that also recognizes that Russia would be an expansionist power, as the theory would predict, and one that responds accordingly with that recognition. Therefore, rather than drawing a broad grand strategic identity on the restraint movement as “good realists,” adherents of offensive realism should reconsider their advocacy of restraint and consider the potential internal contradictions that may come with marrying the theory’s descriptive assumptions on international politics with such a grand strategic approach.
Will Kielm ’23 served as the President of the AHS chapter at the University of Michigan, where he earned a Bachelor’s degree in Public Policy.
 Daniel Deudney and G. John Ikenberry, “Misplaced Restraint: The Quincy Coalition Versus Liberal Internationalism,” Global Politics and Strategy 63 (27 July 2021): 7-32.
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 Schweller, 927-930.
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 John Herz, “Idealist Internationalism and the Security Dilemma,” World Politics 2, no. 2 (1950): 171–201.
 Robert Jervis, “Cooperation Under the Security Dilemma,” World Politics 30, no. 2 (January 1978): 167-214.
 Jack Snyder, Myths of Empire: Domestic Politics and International Ambition (Ithaca, NY: Cornell University Press, 1991).
 John J. Mearsheimer, The Tragedy of Great Power Politics (New York, NY: W. W. Norton & Company, 2001).
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 “Conversations in International Relations: Interview with John J. Mearsheimer (Part II),” International Relations 20, no. 2 (26 July 2016), https://journals.sagepub.com/doi/10.1177/0047117806063851.
 Charles L. Glaser, “The Security Dilemma Revisited,” World Politics 50, no. 1 (October 1997): 171-201.
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 Gholz et al., 6.
 John J. Mearsheimer, The Great Delusion: Liberal Dreams and International Realities (New Haven, CT: Yale University Press, 2018).
 John J. Mearsheimer and Stephen M. Walt, “The Case for Offshore Balancing: A Superior U.S. Grand Strategy,” Foreign Affairs 95, no. 4 (July/August 2016): 70-83.
 Andrey A. Sushentsov and William C. Wohlforth, “The tragedy of US–Russian relations: NATO centrality and the revisionists’ spiral,” International Politics 57 (20 March 2020): 427–450.
 John J. Mearsheimer, “Why the Ukraine Crisis Is the West’s Fault: The Liberal Delusions That Provoked Putin,” Foreign Affairs 93, no. 5 (September/October 2014): 77-89.
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 Stephen Walt, “Does Anyone Still Understand the ‘Security Dilemma’?,” Foreign Policy, 26 July 2022, https://foreignpolicy.com/2022/07/26/misperception-security-dilemma-ir-theory-russia-ukraine/.
 John J. Mearsheimer, “John Mearsheimer on why the West is principally responsible for the Ukrainian crisis,” The Economist, 19 May 2022, https://www.economist.com/by-invitation/2022/03/11/john-mearsheimer-on-why-the-west-is-principally-responsible-for-the-ukrainian-crisis.
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