SOURCE:
https://tnsr.org/2018/11/disentangling-grand-strategy-international-relations-theory-and-u-s-grand-strategy/

Grand Strategy

Disentangling Grand Strategy: International Relations Theory and U.S. Grand Strategy

Paul C. Avey, Jonathan N. Markowitz, Robert J. Reardon

Paul C. Avey, Jonathan N. Markowitz,

This article assesses the underlying sources of disagreement among competing scholarly treatments of U.S. grand strategy. It argues that much of the debate centers on differing conceptions of the roles of power and domestic and international institutions in international politics. In addition, it cuts through conceptual confusion that clouds much of the debate by clearly delineating interests, objectives, and policy levers. This framework will allow existing and future research to more usefully address and advance the debate. Finally, it provides a baseline with which to assess initiatives by U.S. administrations.

The United States “stands at a crossroads in history,” the George H.W. Bush administration asserted in its National Security Strategy in January 1993. The world, it argued, had been “radically transformed” to an era that “holds great opportunities … but also great dangers.” Twenty-two years later, the Barack Obama administration stated that “at this pivotal moment, we continue to face serious challenges to our national security, even as we are working to shape the opportunities of tomorrow.” The National Security Strategy produced by Donald Trump’s administration last year similarly, if somewhat more ominously, highlights both dangers and opportunities.1 In each strategy document, American power is seen as vital to addressing the shifting international environment. Yet there are still plenty of areas of disagreement, and outside the Beltway the debate extends even further.

What is America’s role in the world? And what policies would best realize those goals? These questions are at the heart of differing conceptions of American grand strategy. Though frequently conflated, they remain distinct. As a result, while there is no shortage of statements on U.S. grand strategy, there is little consensus on the basic contours of the debate, let alone which course would best serve American interests. Disagreements frequently arise due to fuzzy thinking about whether policy prescriptions follow from different conceptions of what the national interest should be or debates about the evidence supporting competing claims. At this critical juncture — to borrow a cliché from past national security strategies — it is worth stepping back to evaluate the competing grand-strategic positions that seek to enhance America’s national interests.

A more fruitful debate would focus on claims about how policy means can or cannot realize U.S. interests rather than the nature of those interests. The former task is amenable to rigorous research; the latter rests on normative judgments that must be settled through a political process. Scholars can and should contribute to that process.2 In doing so, however, they should be clear about whether they are making a claim about a policy achieving a particular interest or whether they are agreeing with that interest. A debate built on evidence of the links between means and ends can assess the efficacy of prescriptions and help diagnose situations. By contrast, reasonable individuals can disagree on how to weigh specific values and risks.3 This article, therefore, focuses on the former while acknowledging the importance of the latter.

A debate focused on the relation between means and ends has to meet four conditions. First, there must be some agreement on America’s national interests. Second, the underlying theories for each position on grand strategy must be clearly identified. Third, scholars must then evaluate the logic of each side’s theories and derive testable propositions. Fourth, those propositions must be subjected to rigorous assessment. Currently, debate over grand strategy satisfies few, if any, of these conditions. Satisfying all four is beyond the scope of one article. Therefore, we aim to develop a framework that addresses the first two and in so doing provide a necessary foundation for future research to evaluate trade-offs across grand strategies and rigorously assess competing claims.

We focus on the scholarly debate, but this is not merely an exercise in academic navel-gazing. Duke political scientist and former National Security Council staff member Peter Feaver reminds us that “every policy choice is a prediction that can be expressed in the type of theory language familiar to academic political science: if we do X then Y will (or will not) happen.” Policymakers rely on an “implicit causal theory that links inputs to outputs.”4 Similarly, a 2011 survey of former national security officials found that they sought “frameworks for making sense of the world they have to operate in,” which social scientists would call theories.5 True, grand strategy must be adaptive and, at times, policymakers are reduced to reaction. Even in those cases, though, leaders draw on some set of notions about how the world works as they respond to new situations.6

Policymakers may disregard scholarly research or use it instrumentally to support their own positions, of course. The incentives and focus of scholars and policymakers are different.7 Moreover, policymakers pressed for time are unlikely to keep up with the most recent issues of peer-reviewed journals, though increasingly there are alternative outlets through which scholars can convey their findings.8 Attention to the role that theory plays in grand strategy is, nevertheless, useful for at least two reasons. First, it can shape the studies available to policymakers. Second, it strengthens external critiques of policies for which there is little empirical support.

Building our framework requires setting aside the normative components of the debate and focusing on how different grand-strategy positions advance a common set of interests. We do so by holding national interests constant to establish a common baseline.9 We identify four major ideal-type grand-strategy positions deductively according to their underlying theoretical principles. First, differences in conceptions of power divide the positions into two overarching camps: those that adopt some variant of balance-of-power realism and those built on hegemonic stability theory (Table 1). This dichotomy alone obscures differences between grand strategies. Thus, the second part of our argument incorporates the role of international and domestic institutions (Table 2). We label these four schools restraint, deep engagement, liberal internationalism, and conservative primacy.10 Others have highlighted how theory shapes thinking on foreign policy and grand strategy.11 We extend these insights to offer a novel categorization of the contemporary scholarly debate that clarifies the sources of disagreement over interests, objectives, and tools.

Table 1. Power and Grand Strategy Positions

Balance of Power	Hegemonic Stability Theory
Restraint	Deep Engagement Liberal Internationalism Conservative Primacy

Table 2. Institutions and Grand Strategy Positions

		International Institutions Critical to Secure U.S. Interests
		Yes	No
Domestic Institutions Critical to Secure U.S. Interests	Yes	Liberal Internationalism	Conservative Primacy
Domestic Institutions Critical to Secure U.S. Interests	No	Deep Engagement	Restraint

Parsing the contemporary grand-strategy debate this way is useful for several reasons. First, it provides a general and clear understanding of the landscape. Moreover, critics of our categorization can use this as a foil to make explicit what additional theories should be considered to generate alternative grand-strategy positions. Second, our deductive approach allows the identification of four positions in the debate that inductive approaches can obscure. For example, scholars who agree on one prescription, such as a robust U.S. military presence abroad, may disagree on others, such as the 2003 invasion of Iraq. Third, our framework clarifies the links between the oft-conflated concepts of theory, interests, objectives, and policy tools. Separating the debate along these conceptual levels adds the precision needed to transform broad visions into specific propositions. It also helps to clarify when scholars’ policy prescriptions hinge on normative preferences as opposed to theory and evidence.

In mapping how diverse worldviews inform grand strategy, we cannot address every aspect of the debate. We do not seek to demonstrate the superiority of one position or its potential domestic public appeal, and we necessarily gloss over minor disagreements in the interest of outlining ideal-types.12 We are also unable to engage critical treatments of grand strategy.13 Finally, we do not attempt an account of grand strategy in the Trump administration. A lively discussion of this subject is ongoing, with widely divergent conclusions.14 We nevertheless provide a baseline with which to judge when the Trump administration is proposing novel positions of grand strategy, borrowing from discrete (and perhaps contradictory) approaches, and when policy is actually very much in line with existing formulations. For example, our framework could account for a more assertive nationalist position that blended elements of hegemonic stability (deep engagement, liberal internationalism, and conservative primacy) with skepticism toward the importance of both domestic and international institutions (restraint). We leave the ultimate categorization to others.

The rest of this article proceeds in three parts. First, we develop our argument by unpacking the terms we use to characterize the dimensions of the debate. Next, we use this framework to outline four grand-strategy positions. We conclude by summarizing major areas of disagreement and ways to advance the debate.

The Framework

In this section, we separate and define the concepts of interests, objectives, and policy tools. Interests are the highest purposes of the state that grand strategy seeks to attain. To achieve their interests, states set objectives (such as preventing a Eurasian hegemon) and utilize specific policy tools (such as alliance commitments) to attain objectives.

There is considerable disagreement over how to define grand strategy.15 Hal Brands reviews multiple definitions and concludes that grand strategy is “the conceptual logic that ensures that [foreign policy] instruments are employed in ways that maximize the benefits for a nation’s core interests.”16 In an important recent article, Nina Silove argues that scholars and practitioners have employed three discrete concepts of grand strategy over time, which she labels grand principles, grand plans, and grand behavior. All three share a focus on long-term and multiple elements of state power, as well as the relationship between ends and means.17 Our emphasis on underlying theoretical principles highlights the role of grand principles. We suggest that in order to advance the grand strategy debate it is necessary to demonstrate how underlying principles guide both behavior and plans to advance the national interest. Specifically, by pursuing objectives with a particular set of policy tools. We adapt these definitions to the United States, defining grand strategy as the U.S. theory of how it can maximize American security, prosperity, and liberty.

The assumption that U.S. interests are constant is controversial, so we want to unpack our logic.18 First, this assumption establishes a baseline for competing grand-strategy prescriptions. Without this assumption, it is impossible to isolate the impact of each side’s theoretical assumptions on its prescribed policy prescriptions.19 For instance, one might consider U.S. alliance commitments as a tool that may help obtain certain objectives. By contrast, labeling a U.S. alliance commitment as an interest indicates that whether the alliance helps or harms U.S. objectives does not matter; the alliance commitment is itself an intrinsic interest to pursue.20 Social science tools are ill-suited to assess whether a national interest is normatively appropriate or not. We therefore focus on the theoretical links between specific tools and objectives that advance a particular policy interest. In other words, we examine how variation in worldviews informs disagreements over what objectives and policy levers will best maximize U.S. interests, rather than what those interests should be.

Much of the debate over grand strategy centers on the presence or absence of links between advancing stability, welfare, and freedom abroad with the well-being of the United States at home.

The second virtue in limiting U.S. core interests to security, domestic prosperity, and domestic liberty is that most participants in the debate explicitly or implicitly adopt these interests. Generally, advocates for expansive grand strategies argue that these have been and should be U.S. national interests.21 And even those favoring a reduced U.S. role in the world frequently assert interests beyond security. For example, Stephen Walt writes that the “central purpose of U.S. foreign policy is to make Americans safer and richer, and to preserve our political values here at home.”22 Similarly, Christopher Preble argues that a less activist grand strategy would enhance American security, prosperity, and liberty.23 Barry Posen defines security to include a state’s power position, which is in turn the “sum total of a state’s capabilities … [including] population size, health, and skill [and] economic capacity of all kinds.”24 Domestic prosperity thus finds its way into security. To be sure, there is disagreement on the content of these concepts. For instance, domestic liberty has various meanings and the number of Americans who could claim liberty has expanded over time. Yet, as Henry Nau notes, “the core classical liberal belief in individual liberty and equality … binds all Americans, conservatives and liberals alike.”25

We assume that the core U.S. interests are the security, prosperity, and liberty of the American people, not the world. As Posen notes, advancing “the economic welfare or liberty of people abroad” may enhance U.S. interests, but that need not be the case.26 Much of the debate over grand strategy centers on the presence or absence of links between advancing stability, welfare, and freedom abroad with the well-being of the United States at home. Importantly, this is a narrower use of the term “interests” than is common in the policy discourse. Here we refer strictly to core U.S. values, as opposed to more instrumental objectives (e.g., preventing the rise of a Eurasian hegemon) that — although commonly referred to as “interests” — are pursued as means of maximizing the core interests we identify. This distinction helps to clarify how the schools of grand strategy differ more on how to achieve core U.S. interests than on what those core interests ought to be.

We define grand strategy objectives as the real-world outcomes a state seeks to achieve in order to advance its interests. Objectives are instrumental to interests: Choosing which objectives to pursue depends on one’s theory of what objectives will best maximize interests given internal and external constraints. For example, some argue that maintaining stability in Eurasia is both affordable and necessary for attaining U.S. interests, while others argue that it is too costly or unnecessary. Finally, policy levers or tools are the instruments states employ to realize their objectives. A state’s choice to invest in its diplomatic corps or military forces is a lever that can affect the probability of realizing a given objective that would further an interest. Moreover, just as objectives are instrumental to interests, the specific policies a state adopts are means to realizing its objectives.

We restrict our analysis to four specific policy levers: military force structure, security commitments, military deployments, and the use of force. States can rely on additional grand strategy tools, but we focus on military tools for several reasons. Much of the grand-strategy debate centers on the role of military power, and the most intense schisms involve the deployment of military forces and the extension of alliance commitments. This is not surprising: Extending alliance commitments, deploying troops, fighting, and acquiring the necessary military capabilities for each involve significant political, economic, moral, and human costs. There is also a practical concern: No article can focus on every U.S. policy tool. Limiting the focus allows us to more specifically describe and define the differences between grand strategies.

Four Grand Strategies

In this section, we outline each of the ideal-types of grand strategies. We focus on each strategy’s underlying theory and its relation to objectives and policy levers. Table 3 summarizes the arguments along each dimension.

Table 3. Grand Strategy Types

		Restraint	Deep Engagement	Liberal Internationalism	Conservative Primacy
Theoretical Anchors		Balance-of-Power Realism	Hegemonic Stability Theory (HST)	HST + Institutionalism	HST + Classical Liberalism
	OBJECTIVES
Regional Priorities		Balance in Core	Stability in Core	Global Stability	Global Stability
Peer Competitor		Prevent	Prevent	Incorporate Into Institutions	Prevent
Globalization		Allow	Promote	Promote	Promote
Institutions		Indifferent	Promote	Promote	Wary
Counterterrorism		Minimal	Moderate	Expansive	Expansive
Counter Proliferation		Minimal	Expansive	Expansive	Expansive
Human Rights Promotion		Minimal	Minimal	Expansive	Moderate-Minimal
Democracy Promotion		Minimal	Minimal	Expansive	Expansive
	POLICY LEVERS
Committments		Reduce	Maintain	Expand	Expand
Force Structure		Reduce	Maintain	Maintain	Expand
Troop Deployments		Offshore	Forward in Core	Global	Global
Use of Force		If Balancing Fails	When Core Threatened	Multilateral When Objectives Threatened	Unilateral When Objectives Threatened

Restraint

Theoretical Anchor

Balance-of-power realism provides the intellectual foundation for restraint, or what some label an “offshore balancing” grand strategy. This theoretical anchor makes several core assumptions: The international system is anarchic, states cannot fully know the intentions of other states, and states want to survive. “Because there is no government to protect them and they cannot know the intentions of others,” write Sebastian Rosato and John Schuessler, “great powers must ultimately provide for their security.”27 One state’s efforts to make itself more secure can create insecurity for others. This is the basis of the security dilemma that plays an important role for the restraint position.28 Systemic constraints and the distribution of power are the key causal factors in shaping international outcomes, while international and domestic institutions play a marginal role. Alongside, but distinct from, the focus on the international system, the restraint position argues that nationalism remains a powerful motivating force.29

The desire to survive imbues societies with strong incentives to resist outside influence. That is why states tend to balance rather than bandwagon. States with sufficient means work to block or undermine opponents by building up their own military capabilities, allying with states, or militarily challenging an opponent’s interests. Efforts to project power and counterbalancing occasionally lead to escalating spirals of hostility that can result in an arms race or conflict. There is disagreement about which behaviors provoke balancing, but there is consensus that the more geographically proximate and active a state is, the more likely it is that its actions will provoke reactions by capable states.30 The emphasis on ability to balance is critical. Weak states not directly targeted by a great power may be able to do little and, therefore, simply bandwagon or stay out of the way until they find themselves directly in a great power’s crosshairs.31 The basic balancing logic can extend to non-state actors, which will use asymmetric strategies (e.g., terrorism) to challenge the great-power policies they oppose.32

Many link this restraint position to defensive realism.33 Yet the U.S. geographic and power positions allow offensive realists to coherently advocate a policy of restraint. Offensive realism predicts that states will seek to expand when the benefits outweigh the costs. The United States’ position as the only major power in the Western Hemisphere provides a high level of security and prosperity. The costs associated with U.S. activism therefore outweigh the minimal benefits in the absence of a potential hegemon abroad.

Objectives

The focus on balancing and nationalism directly informs the restraint position’s contention that a short list of objectives best advances American interests. First, restraint focuses on thwarting any major threats to the American homeland. Second, the United States must prevent the emergence of a hegemon in Europe, Northeast Asia, or the Middle East. A rival could utilize the region’s power potential to endanger U.S. territory or block U.S. commerce. A hegemon in the Middle East, for example, could endanger energy flows, raising the global price of key commodities, which would in turn harm the U.S. economy.34 Finally, the United States must deny another state the ability to command the global commons of the “sea, space, and air.”35 If others command the commons, then the United States might find its homeland vulnerable to attack. In the long run, this could also undermine the U.S. economy.

Restraint looks at the world today and sees few states capable of threatening these objectives. Distance and the American nuclear arsenal deter major assaults on U.S. territory. No state can unite European or Asian power potential in the near term, though China may be able to do so in the medium to long term, necessitating a cautious balancing approach.36 Preventing the emergence of a hegemon in the Middle East requires minimal U.S. investment because the regional powers are very weak. Moreover, global markets are robust and not easily disrupted.37

The focus on balancing and nationalism directly informs the restraint position’s contention that a short list of objectives best advances American interests.

The restraint position does not identify regional stability as a grand-strategy objective.38 To begin with, instability abroad does not directly affect American security. Moreover, the tendency to balance causes others to contest U.S. efforts to impose stability, generating security dilemmas that actually can generate instability. Restraint prefers letting regional actors balance other regional actors. This may lead to conventional arming, the formation of new alliances, and even nuclear proliferation as others supply their own security. As more states provide for their own security, the United States can reduce its defense burden, enhancing U.S. prosperity and liberty without sacrificing security.39 U.S. allies do not behave this way today, the restraint position argues, because they are “cheap-riding” while the United States foots the bill for security.40 Worse, these actions may be creating a moral hazard, emboldening allies to act recklessly, which can in turn entrap the United States.

Restraint considers terrorism an enduring challenge but not one that rises to the level of a grand-strategy objective. This grand-strategy position takes “seriously the threat from international terrorism,” notes Michael Desch, but it “also put[s] it into perspective.”41 Expansive counterterror policies can provoke backlash. As Robert Pape argues, “U.S. ground forces often inadvertently produce more anti-American terrorists than they kill.”42 Although terrorist acquisition of a nuclear weapon would be a “game changer,” the probability of that occurring is low.43 States are unlikely to allow their nuclear weapons or fissile material to fall into the hands of a terrorist organization and risk losing control over how the material is used or risk potential retaliation from the terrorist’s target.44 Rather than relying on military tools, the United States can help secure stockpiles and prevent accidents by sharing safeguard technology and best practices with other nuclear capable states.45

Although few restraint proponents advocate nuclear proliferation, most do not consider nonproliferation a grand-strategy objective. Aggressive nonproliferation efforts are likely to encourage proliferation among hostile states as they seek to balance the United States.46 Additionally, restraint adopts the nuclear-optimist position that nuclear weapons reduce conflict.47 As long as the United States maintains its nuclear arsenal, deterrence will prevent nuclear attacks. Regional nuclear-armed states can deter regional aggression. Thus, Posen accepts that with the restraint position, “some nuclear proliferation would be tolerated.”48 This may cause the United States to lose some power-projection ability, but restraint prefers that the United States do less in the current international environment.

Restraint also does not count democracy promotion or humanitarian intervention among its objectives. Restraint does not oppose democracy or foreign aid, but its proponents believe that promoting either is inappropriate as part of a grand strategy. Whereas democracy promotion is difficult and unnecessary for advancing U.S. interests, humanitarian interventions can create failed states, generate havens for terrorists, and invite diplomatic backlash. A number of alternative diplomatic and foreign aid initiatives may, in the end, be more effective and save more lives.

Policy Levers

The restraint approach seeks to reduce U.S. defense commitments, forward deployments of troops, the frequency of using force, and the size of the U.S. military. Despite sharing a common theoretical base and set of objectives, individual scholars within this domain differ on the scope of reduction. The broadest divide is between those advocating modest versus major reductions. This reflects diversity in assessments of the balance of power, technology, preferences for hedging against geopolitical uncertainties, and estimates of domestic political feasibility. While these differences are important, they are outside the shared theoretical framework.49 We do not, therefore, treat these differences as discrete grand strategies. Proponents of restraint argue in favor of reducing U.S. security commitments and forward deployments of troops. At the extreme end of the spectrum, scholars in this group advocate ending nearly all military commitments and bringing U.S. troops home.50 More moderate positions agree on reducing the U.S. role in NATO and Europe, where Russian weakness and Western European wealth negate the need for U.S. involvement. U.S. air and naval power may remain in the Middle East, but the United States would remove ground forces and no longer support regimes against domestic opposition. Only in Asia, as a hedge against the rise of China, would sizable U.S. forces — primarily air and sea — and defense commitments potentially remain.51

The objectives of restraint suggest the United States ought to use force rarely. It would do so only if a state stands poised to attain hegemony in Europe, Asia, or the Middle East, or if a state makes a bid to command the commons. Additionally, the United States would use minimal force to degrade and contain terrorist organizations that have the desire and ability to strike the United States.52 The limited global role would allow significant reductions in the current U.S. force structure. In particular, force structure would shift to one that privileges the Navy and Air Force with light, highly mobile ground forces that proponents of restraint contend would result in large savings.

Deep Engagement

Theoretical Anchor

Hegemonic stability theory provides the underlying principles for the deep engagement approach to grand strategy.53 This position shares much with what some have labeled “selective engagement.”54 Deep engagement draws on a separate branch of realism than the restraint position and argues that balancing is not feasible when one state’s material capabilities far exceed those of all others. States are more likely to bandwagon with, rather than balance against, the hegemon. Not only is balancing unlikely, according to this framework, but the world is more peaceful and prosperous when there is a preponderance of power.55 The hegemon can utilize its superior military and economic tools to provide public goods, such as regional security, that underwrite a stable international order. The provision of security alleviates regional security dilemmas and deters aspiring powers from challenging the hegemon’s authority.56 Absent the hegemon’s presence, regional balances of power will not form and costly arms races will occur. Moreover, a distant hegemon will be dragged into the conflict, thereby harming its interests. Globally, the clear preponderance of power makes conflicts over prestige unlikely, removing another source of war. Thus, escalating spirals of hostility are unlikely at both the global and regional levels.

Advocates of deep engagement argue that the benefits of maintaining the hegemonic order outweigh the costs. Costs are low because other states are unlikely to balance and military spending is not a major drain on resources.57 Moreover, peripheral wars are choices rather than necessities, and so do not generate major costs for this strategy so long as the hegemon exercises prudence.58 The hegemon also benefits from increased security, extracts enormous privileges from the system, and enriches itself through the rise in global prosperity.59 The hegemon’s ability to shape international institutions facilitates order and lowers transaction costs for managing the international system. For instance, the hegemon can use economic institutions to mold the global economic system to its comparative advantage.60 International security institutions allow the hegemon to coordinate with allies to maintain regional stability.61 However, in contrast to liberal internationalism, proponents of deep engagement argue that such institutions are unlikely to be effective in the absence of a hegemonic state powerful enough to underwrite them.

Objectives

Deep engagement aims to deter threats to the homeland and the global commons. It also focuses on maintaining stability in three key regions — Asia, Europe, and the Middle East — rather than just preventing a hegemon from emerging. Thus, Stephen Brooks and William Wohlforth advocate economic globalization, promoting institutions, defending allies, and preventing conflict that would threaten the U.S.-led international order.62 Proponents of deep engagement argue that the United States can, and should, continue to lead the international order: It can because it remains the only superpower and its position is durable;63 it should because its presence stabilizes economic and security relations between states. Without a hegemon, regional actors will fail to balance potential peer competitors, harming U.S. security and prosperity. Finally, changes to the status quo adversely affect the United States because the system reflects American interests.

Maintaining a stable, open, and U.S.-led order in the world’s core regions requires that the United States pursue several objectives. First, the United States must oppose the emergence of a regional hegemon and work to dampen strictly regional security competition in key areas. Without U.S. leadership, local balancing will be inefficient. Moreover, security competition generates negative externalities — such as conventional arms racing, nuclear proliferation, and trade disruption — that increase the risk of regional and global instability. In contrast to the restraint approach, deep engagement adopts nuclear pessimism, which highlights the dangers of nuclear accidents, inadvertent escalation, and loose nuclear weapons. These risks outweigh any potential stabilizing effects of nuclear weapons.64 Thus, deep engagement contends that paying the costs associated with protecting American allies helps to deter and contain potential peer competitors and regional instability. This also gives the United States leverage over its allies, minimizing the risk of entrapment.65

Proponents of deep engagement argue that the United States can, and should, continue to lead the international order...

Second, deep engagement aims to protect the United States and its allies from terrorism and violent domestic instability. But it does not view these threats outside of the core regions as major dangers. For example, the risk of a terrorist attack or civil conflict in sub-Saharan Africa is a smaller concern than it would be in Saudi Arabia. Deep engagement might support efforts to prevent failed states, civil war, ethnic conflict, and humanitarian disasters, but only if such outcomes have the potential to threaten stability in the core regions.

Deep engagement supports the spread of democracy but does not view it as a grand-strategy objective because overt democracy promotion can undermine support for other U.S. objectives.66 Efforts to protect human rights through humanitarian intervention or democracy promotion distract leaders from core objectives and may lead policymakers to pursue unnecessary or impossible objectives, squander resources, and produce negative externalities.

Policy Levers

Supporters of deep engagement seek to construct a military capable of maintaining existing alliance commitments and troop deployments abroad. These tools serve as the backbone of U.S. influence by deterring adversaries and reassuring allies. Brooks, Ikenberry, and Wohlforth make the point clearly:

The United States’ overseas presence gives it the leverage to restrain partners from taking provocative action. Perhaps more importantly, its core alliance commitments also deter states with aspirations to regional hegemony from contemplating expansion and makes its partners more secure, reducing their incentive to adopt solutions to their security problems that threaten others and thus stoke security dilemmas.67

To this end, the United States has constructed a set of commitments that include formal defense pacts with 68 countries that, together with the United States, represent 75 percent of world economic output.68 America’s commitment to NATO and the security structures in the Middle East and Asia should continue. Moreover, contrary to the restraint approach, the deep-engagement position argues that forward-deployed forces are necessary to maintain command of the commons and allow the U.S. presence to surge in an emergency. International commitments and U.S. troop presence also encourage intelligence sharing and cooperation in counterterrorism efforts, as well as reducing domestic instability in these regions.

Proponents of deep engagement argue that critics overstate the costs of this grand strategy. For one thing, offsetting arrangements with allies defrays the financial costs of deploying troops abroad. In terms of terrorism, U.S. troops may contribute to anti-Americanism, as some claim, but they are hardly the decisive factor.69 Were most U.S. troops to come home tomorrow, the terrorist threat would not disappear, nor would much money be saved. Regarding entrapment, alliances allow the United States significant freedom to maneuver and tend to give Washington more influence over its weaker partners.70

In this framework, military force is a tool to maintain, not alter, the status quo. Hence, deep engagement supports the use of force to protect existing commitments but does not support using military force to spread democracy or, except in extreme cases, remove human rights violators from power. As Brooks and Wohlforth write,

[T]hose who advocate ambitious projects to assertively spread democracy and liberal principles and foster dramatic improvement in human rights, by the sword if necessary, make the same mistakes as proponents of pulling back: they fail to appreciate the major benefits America derives by sustaining its long-standing grand strategy.71

Proponents of deep engagement seek to maintain U.S. force-structure projections made toward the end of the Obama administration but are not opposed to modest increases. This level of military power is necessary to maintain existing commitments and deployments, and it requires an amount of military spending that is both affordable and likely to decrease as a percentage of GDP over time.72 A larger military is unnecessary because deep engagement does not seek to undertake new military missions or commitments outside core regions.

Liberal Internationalism

Theoretical Anchor

Liberal internationalism rests on a combination of hegemonic stability theory and neoliberal institutionalism. This view of grand strategy depends on the “decentralized model” of hegemonic stability, in which it is the hegemon’s “benevolent leadership” more than its coercion of states that ultimately maintains the international order.73 Liberal internationalism’s central tenet is that the hegemon creates and maintains an order built on “rules and institutions that advance collective security and cooperation among democracies.”74 It holds that a stable international order can arise when a hegemon is able and willing to use its power to overcome collective action problems — in which states each have an incentive to free ride on the efforts of others — and provide international stability as a public good. Liberal internationalism does not accept that the hegemon’s power alone is sufficient, instead arguing that hegemonic leadership must command legitimacy. That legitimacy depends on upholding the interests of the other states in the system rather than coercing states to adhere to the hegemon’s rules. To accomplish this, the hegemon must tie its own hands by adhering to the same rules as other states and allowing a role for non-state actors.75 By constructing effective, relatively flat (as opposed to hierarchical) international institutions, the hegemon restrains its ability to act coercively, which in turn enhances the legitimacy and stability of the order. Institutions also facilitate cooperation by reducing transaction costs, monitoring and enforcing agreements, and overcoming collective-action problems. Ultimately, a thick web of institutions can lock in the order and allow it to outlive the hegemon’s inevitable decline. Rising great powers can then be co-opted into supporting and perpetuating this order.76 Institutions help overcome the nefarious consequences of anarchy touted by balance-of-power realists.

Liberal international-relations theories of the economic and domestic-political underpinnings of international cooperation strongly inform liberal internationalism.77 In particular, proponents of liberal internationalism contend that the promotion of open and free trade (economic liberalism) and the global spread of democracy (republican liberalism) are critical pillars of a stable and peaceful international order. As Anne-Marie Slaughter argues, the “origins of international conflict and cooperation lie in the political and economic micro-foundations of individual societies.”78 Democratic states are unlikely to go to war with one another and can cooperate to form security communities.79 Market democracies will pursue globalization with the free flow of goods, services, and ideas across borders. This type of economic interdependence not only promotes peace, by raising the costs of conflict, but also enhances prosperity.

Objectives

The core objective of liberal internationalism is the maintenance and expansion of a U.S.-led liberal international order embedded within a dense network of international institutions.80 As Slaughter has written, the “next U.S. president should adopt a grand strategy of building and maintaining an open international order based on three pillars: open societies, open governments, and an open international system.”81 Thus liberal internationalism parts company with deep engagement by considering the incorporation of liberal elements into the international order the very bedrock of U.S. grand strategy.

Liberal internationalism considers the end of unipolarity and the rise of one or more rival great powers to be inevitable, but in contrast to the other grand strategies it opposes efforts to contain them.82 Instead, proponents of liberal internationalism argue that by building a thick web of international institutions, the United States can co-opt potential rivals into the existing order and provide them a stake in maintaining it. The end of the Cold War created a unique historical moment and an unparalleled opportunity for the United States to lock in an international order amenable to its interests.83 During this window of opportunity, the United States should use its power for building institutions, advancing democratic institutions and norms, promoting free markets, and reducing barriers to international trade — albeit while acting within the rules of the order it has constructed. Institutions, proponents of liberal internationalism argue, are “sticky.” Once states become enmeshed in a sufficiently thick, rules-based liberal international order, the benefits this order provides and the costs of dismantling it create powerful incentives for future great powers to continue to support it.84 Friends and potential rivals gain from the hegemon’s provision of global public goods like security and stability. Institutions also reassure other states that U.S. leadership is benign by constraining U.S. behavior. Although the United States may possess the military and economic power to violate institutional rules, doing so would undermine its international legitimacy.85

Liberal internationalism considers the end of unipolarity and the rise of one or more rival great powers to be inevitable, but in contrast to the other grand strategies it opposes efforts to contain them.

Liberal internationalism considers the spread of democracy and globalization a keystone to global stability and a central grand-strategy objective. Liberal internationalism therefore advocates protecting established and nascent democracies, even to the point of providing military support to domestic democratic opponents of autocratic regimes. This democratizing impulse was the basic rationale behind the Clinton administration’s “democratic enlargement” policy, which expanded NATO eastward in the 1990s.86 As Slaughter puts it, the United States must continue its policy of “supporting liberal democratic parties and institutions in countries determining their own political future. … The twenty-first century, like the twentieth century, must be made safe for democracy.”87 Promoting globalization can also foster the development of a middle class, a core constituency for democratization in developing countries.

Liberal internationalism highlights the importance of maintaining regional stability. Regional arms races and conventional conflict undermine the rules-based international order and end up sucking the United States into conflict. History has shown that “aggressors in faraway lands, if left unchecked, would someday threaten the United States.”88 For liberal internationalism, the Sept. 11, 2001, attacks demonstrated how internal and external stability can create conditions that can lead to direct harm to the United States.

Proponents of liberal internationalism consider international terrorism, the proliferation of nuclear weapons, and gross human rights violations to be significant threats to global order. These concerns are compounded by general suspicions of authoritarian and illiberal groups and a skepticism that they can reliably be deterred. Nuclear proliferation and terrorism can combine in particularly pernicious ways. Ikenberry and Slaughter assert that the “threat of nuclear terrorism looms greater than any other nuclear threat because of the limits of traditional concepts of deterrence against adversaries who would willingly martyr themselves.”89 To states, on the other hand, nuclear proliferation generates instability and imposes limits on America’s ability to act against challengers to the liberal international order. Human rights violations can undermine nascent liberal movements and breed regional instability.

Policy Levers

Liberal internationalism holds that U.S. military dominance currently underwrites the liberal international order. The United States must, therefore, maintain the military capabilities and alliances necessary to deter and defend against revisionist, anti-liberal challengers.90 As Ikenberry and Slaughter write, liberal internationalism’s objectives “require a continued high level of U.S. defense spending.”91 The United States should maintain and expand its commitments and, where necessary, its troop presence. This is particularly true for nascent democracies outside Western Europe. “The United States,” Ikenberry argues, “should recommit to and rebuild its security alliances. … The updating of these alliance bargains would involve widening the regional or global missions in which the alliance operates and making new compromises over the distribution of formal rights and responsibilities.”92 Although the regional emphasis may differ by scholar, liberal internationalism supports an expansion of troops in specific cases as a hedge against potential illiberal challenges. For instance, as noted by Michèle Flournoy, former U.S. undersecretary of defense for policy, and Janine Davidson, former U.S. deputy assistant secretary of defense for plans, “The cornerstone of forward engagement [is] positioning U.S. troops in vital regions to help deter major conflicts and promote stability, particularly in Asia and the Middle East.”93

At times it will be necessary to use force to attain American objectives. This can include the defense of emerging democracies, but liberal internationalism does not advocate the constant use of force to spread democracy. It emphasizes multilateralism, though not necessarily universal support, as a way to build legitimacy for any use of force. Thus Slaughter contends that “if the need for international action is great, the international community must turn to broadly representative regional institutions to authorize and implement intervention.”94 Democratic communities can legitimize U.S. action when broader forums are not supportive.95 Concerns over human rights violations led many proponents of liberal internationalism to support the Iraq War in 2003 and the intervention in Libya in 2011.96 As Slaughter notes, “R2P, [the Responsibility to Protect] has gone deeply out of fashion, but that is surely temporary.”97 The initial stages of humanitarian intervention may require the kind of forces that only the United States is in a position to supply.

Conservative Primacy

Theoretical Anchor

Conservative primacy is a broad family that includes, but is not limited to, neoconservatives, conservative internationalists, and conservative realists.98 It is consistent with much of what Brands labels “a better nationalism” and Colin Dueck calls “conservative nationalism.”99 To be sure, there are a number of disagreements between self-described members of each group. Those disagreements are narrow enough — and the differences with alternative grand-strategy positions wide enough — to justify treating them together as an ideal-type grand strategy. We adopt the term conservative primacy because it captures the core shared theoretical underpinnings driving several, though by no means all, self-labeled conservative positions.100

Conservative primacy shares with liberal internationalism a focus on domestic institutions but parts company when it comes to international institutions.

Specifically, conservative primacy formulations of all types combine classical liberal assumptions and hegemonic stability theory to arrive at more assertive grand-strategic prescriptions. These prescriptions rest on a variant of hegemonic stability theory that combines “benevolent” and “coercive” elements.101 The hegemon’s rule must be benevolent in that the international order it establishes must command legitimacy among other states. This legitimacy arises when core liberal values are shared. Because liberal, democratic states have a shared set of interests, a liberal democratic hegemon’s efforts to establish an international order will command legitimacy even when this requires the unilateral exercise of military force. Indeed, the hegemon’s legitimacy rises among its fellow liberal democracies when it exercises power to defend the international order against nondemocratic challengers. Absent this leadership, dangerous threats will multiply. As Eliot Cohen, Eric Edelman, and Brian Hook state, a “strong United States is essential to the maintenance of the open global order under which this country and the rest of the world have prospered since 1945 … the alternative is not a self-regulating machine of balancing states, but a landscape marked by eruptions of chaos and destruction.”102

Conservative primacy shares with liberal internationalism a focus on domestic institutions but parts company when it comes to international institutions. For conservative primacy, behavior is largely driven by regime type rather than the distribution of power. “Democracies,” Charles Krauthammer wrote, “are inherently more friendly to the United States, less belligerent to their neighbors, and generally more inclined to peace” than illiberal regimes.103 International institutions are suspect, particularly those that grant equal status to both democracies and autocracies, as they empower and legitimize tyrannical regimes. Because democratic regimes are more likely than autocratic ones to be bound by international rules, international institutions restrain the states that need a free hand to uphold the international order, while permitting challengers of the liberal order greater freedom of action. Thus, international institutions can have an important effect on state preferences (contra restraint) but only among democratic states (contra liberal internationalism).104

In sum, conservative primacy’s various permutations share several core features. First, a belief that illiberal (both politically and economically) state and non-state actors are sources of danger. In the wake of the Iraq War, however, there has been disagreement on how aggressively to promote democracy abroad and widespread skepticism of regime-change adventures. Second, proponents of conservative primacy see the use of American military power as a necessary component of hegemony. Finally, under this grand-strategy position, there is a pronounced skepticism of international institutions.

Objectives

Conservative primacy, like its liberal counterpart, favors the promotion of an international order based on liberal characteristics; in particular, the spread of democracy, capitalism, and free trade. As Condoleezza Rice put it, “An international order that reflects our values is the best guarantee of our enduring national interest.”105 Conservative primacy does not consider such an “international order” to be a rules-based order built on international institutions. In fact, it warns that faith in institutions could lead the United States to abrogate its leadership role while failing to constrain illiberal regimes. The United States ought to remain the sole superpower, albeit sharing the stage with several great powers. Even with a variety of challenges, that hegemonic status is, in this view, durable.106

Conservative primacy prioritizes the spread of democracy and opposition to authoritarian regimes. Unlike liberal internationalism, which argues that democracies can resolve conflicts of interest through peaceful negotiation, conservative primacy holds that maintaining a U.S.-led international order is a globally shared interest and that democratic governments best channel popular support for U.S. hegemony. Authoritarian and “rogue” regimes, on the other hand, are unrepresentative of the populations they govern and therefore do not share the citizenship’s interest in maintaining the international political-economic order established by the United States. Proponents of conservative primacy do not rule out spreading democracy by the sword — many supported the 2003 invasion of Iraq — but they caution against ill-conceived or constant efforts to do so. Because non-democratic regimes are both illegitimate and naturally inimical to the established and popularly supported international order, their very existence is a security threat to the United States and its democratic allies.

Conservative primacy posits that the stability of the international order rests on U.S. power. U.S. primacy and preventing the rise of a great-power rival, particularly an illiberal great power, are therefore core objectives. The focus on regime type and the importance placed on U.S. preeminence in the international system suggests a strategy toward China, for example, that would combine elements of engagement and regime transformation (similar to liberal internationalism) and a balancing approach (similar to deep engagement and, increasingly, restraint). The result is a strategy comparable to Aaron Friedberg’s “better balancing” approach, which “combines continued attempts at engagement with expanded and intensified balancing.”107 It differs from other grand-strategic positions by assuming that engagement is the best tool for moving China toward democracy, when coupled with assertive balancing, and that U.S. balancing efforts do not risk escalation or require reassurance.

Aggressive counter-terrorism is a necessary objective of conservative primacy. According to Dueck, “jihadist terrorists” must be preempted: “The nature of this particular enemy leaves no superior alternative other than an assertive and determined strategy of rollback.”108 Advocates of conservative primacy see an essential link between terrorism and “rogue” states that sponsor terrorist organizations and, therefore, favor strategies that focus on that link. For example, the Bush administration rapidly shifted focus to Iraq after the 9/11 attacks despite Iraq’s lack of connection to those attacks. James Mann describes the thinking of then-Deputy Secretary of Defense Paul Wolfowitz as: “[F]orces behind terrorism in the Middle East were all interconnected … If the United States could defeat [Hussein], it would weaken terrorist groups throughout the Middle East. The issue was broader than Al Qaeda.”109

Nonproliferation is also a critical objective because conservative primacy doubts the efficacy of deterrence when it comes to authoritarian and rogue states. Proponents of this grand strategy are supportive of preventive military action as well as ballistic missile defenses and nuclear counterforce capabilities. Concerns about proliferation of nuclear, chemical, and biological weapons were at the center of the Bush administration’s case to invade Iraq. In the wake of the 9/11 attacks, advocates of the neoconservative strain of conservative primacy within the administration expressed particular concern about “rogue” states such as Iran, Iraq, and North Korea acquiring nuclear weapons. This interacted with the terrorist threat to raise additional worry and played a central role in the development of the Bush Doctrine. More than a decade later, it has informed critiques of the Joint Comprehensive Plan of Action addressing Iran’s nuclear program.110

Policy Levers

Conservative primacy highlights the value of using U.S. military power to achieve American objectives. The tendency to bandwagon will dominate incentives to balance, so there are increasing returns to U.S. global activism with little risk of blowback. By this thinking, a robust troop presence would reassure skittish allies, deter and compel potential adversaries, and establish the means to defeat them should coercion fail.111 As Robert Kagan notes, the

American presence enforced a general peace and stability in two regions [Europe and Asia] that for at least a century had known almost constant great-power conflict. … When the United States appears to retrench, allies necessarily become anxious, while others look for opportunities.112

As for the Middle East, Peter Feaver argues that the U.S. shift to an offshore balancing strategy “proved disastrous for American interests and paved the way for the rise of the Islamic State, forcing Obama to shift back once again to an onshore balancing in the region.”113

Conservative primacy emphasizes alliances with democracies rather than autocracies but makes room for compromise on this issue. Mann explains how conservatives shifted during the Cold War from a position largely consistent with the one set forth in Jeane Kirkpatrick’s landmark 1979 Commentary article and toward more assertively supporting democracy even when it meant challenging the domestic security of anti-communist regimes supportive of the United States.114 Similarly, Nau argues that although “critics often attack such cooperation” with authoritarian regimes “as hypocrisy,” it is necessary to set priorities and be sensitive to “the limitations of both resources and public will to support the end of tyranny everywhere at once.”115 Thus, support for U.S. commitments to non-democratic allies in the Middle East and elsewhere is not inconsistent with the overall tenets of conservative primacy.

Conservative primacy’s emphasis on military power leads to a large force structure and a willingness to use military force to advance U.S. objectives. This view of grand strategy emphasizes what Nau calls “armed diplomacy.”116 The ability and resolve to use force “during negotiations and before an attack when it is a choice, not just after negotiations and in retaliation to an attack when it is a necessity,” is essential to “succeed in negotiations that move freedom forward.” This does not mean conservative primacy favors greater use of force overall. Rather, Nau argues that what is preferable is “the earlier and perhaps more frequent use of smaller force to deter, preempt, and prevent the later use of much greater force.”117 Put differently, conservative primacy focuses on the risk of acting too late, while other grand strategies put greater weight on the risk of acting too soon. A large military is, therefore, essential, allowing the United States to act and bargain from a position of strength.118 The conservative-primacy position contends that current U.S. spending on defense is low by historical standards and can be increased without undermining the domestic economy.

Discussion

We argue that key disagreements over grand strategy hinge on theoretical disagreements about the role of power and institutions in international politics. Regarding power, the core disagreement is between the restraint position, which relies on balance-of-power realism, and the other three grand-strategy positions, which adopt variations of hegemonic stability theory. A focus on power alone, however, would lead to an incorrect portrayal of important elements of the debate. Equally significant are the roles that international and domestic institutions play in international politics. Different understandings of those roles have enormous implications for what specific objectives the United States ought to pursue to maximize its interests. Liberal internationalism focuses on spreading liberal economic, domestic, and international institutions, relying on all three pillars of what scholars label the Kantian tripod.119 Conservative primacy draws on classical liberalism and agrees on the importance of spreading liberal economic and domestic institutions. In contrast to liberal internationalism, proponents of conservative primacy argue that international institutions dangerously constrain U.S. action while allowing illiberal states to pursue agendas inimical to U.S. interests. Deep engagement, on the other hand, is the mirror position of conservative primacy: For its proponents, spreading liberal domestic institutions is often a costly distraction from achieving core objectives. At the same time, deep engagement borrows some insights from institutionalism. Advocates of restraint argue that it is unnecessary, and perhaps even counterproductive, to use military tools to underwrite liberal international or domestic institutions to secure U.S. interests.

Our framework makes several contributions to advancing the grand strategy debate. First, by holding interests constant, we identify four grand strategies that lead to a number of policy prescriptions that claim to maximize a given set of U.S. interests. Having done so, future research will be better able to assess which grand strategy offers the best mix of policies to maximize these interests. One could identify a different set of interests, but whatever interests one identifies must be consistent and carefully separated from objectives. Two recent works help illustrate how failing to adopt this framework can lead to conceptual confusion.

In his important book outlining the tenets of a restraint grand strategy, Posen argues that foreign policy “may have many goals beyond security, including the prosperity of Americans at home,” but that grand strategy seeks to maximize security alone. Yet, as noted earlier, his definition of security includes “power position,” which in turn includes “economic capacity.”120 Posen ultimately suggests that economic capacity, then, is both a means and an end.121 This is problematic because, if it is an end, Posen would need to demonstrate that the objectives of restraint lead it to better advance U.S. economic capacity compared with alternative grand strategies. If it is a means, it would be necessary to make clear that there may be a trade-off between security and prosperity in favor of the former. It would also be necessary to specify the severity of this trade-off to assess whether it is sharp enough to undermine security in the long run. Yet Posen largely sidesteps these issues. In short, on his own terms, Posen’s treatment of the restraint position is incomplete. By clearly identifying and examining the issues that our framework highlights, scholars and policymakers will be better able to directly compare the costs and benefits of each grand strategy to maximize a given set of interests.

It is critical for future research on grand strategies to separate means from ends...

The conflation of interests and objectives is apparent in other works as well. In their careful treatment of deep engagement, Brooks and Wohlforth have done just this, writing that “managing the external environment to reduce near- and long-term threats to U.S. national security” is one of three core U.S. grand-strategy interests that are essential for furthering U.S. security.122 This argument borders on a tautology: The best way to preserve U.S. security is to reduce the threat to U.S. security. More important, it, like Posen, conflates means and ends. Managing the external security environment is a means for maximizing the U.S. interest of security; it is not an end itself. As our framework makes clear, interests or ends must be treated as constant, whereas means should vary depending on evidence regarding their effectiveness in realizing those interests. It is critical for future research on grand strategies to separate means from ends so that officials can clearly understand whether scholars are making claims about what interests the United States should adopt as opposed to what means would maximize a given end.

Next, our framework reveals why analysts across grand-strategy positions may agree on some policy prescriptions but not others. For example, paying attention to underlying theories helps reveal why the policy prescriptions of some restraint proponents, such as John Mearsheimer, Stephen Walt, and Barry Posen, overlap with the policy prescriptions of proponents of more robust grand-strategy positions regarding China but not elsewhere.123 This is intellectually consistent: The restraint position focuses on the importance of preventing hegemons from emerging in areas where regional actors are incapable of mustering sufficient power. In such cases, the balance-of-power logic at the heart of restraint points to the necessity of a powerful outside actor to intervene. Thus, in an early post-Cold War statement of restraint, Eugene Gholz, Daryl Press, and Harvey Sapolsky recognized that an expansive American role was necessary when there was a Soviet peer competitor but was no longer needed once America’s relative power surged after the fall of the Soviet Union.124 It follows that if China occupies a similar geopolitical position, then many restraint proponents would accept a larger U.S. role in balancing against China. Absent that type of peer-competitor, however, restraint’s underlying logic remains centered on allowing regional power balancing to deal with local challenges. To the extent that individual analysts within each grand-strategy position disagree on specific propositions, those divides stem from additional factors — such as disagreements over relative power, changing technology, or normative preferences — that lie outside those underlying theories.

Finally, this article provides a framework for how best to apply existing research to the grand-strategy debate and what additional research should be undertaken. We illustrate this with two examples drawn from each axis of the debate. First, if a U.S. presence abroad provoked rival nuclear proliferation more than it limited allied proliferation this would support the restraint position while undermining alternative approaches to grand strategy. The converse, however, is not necessarily the case. If reduced American involvement caused more proliferation among allies, advocates of restraint may find that acceptable, arguing that it increases regional stability through mutual deterrence. It would then be necessary to consider research from the enduring debate on the consequences of nuclear proliferation for regional (in)stability as well as whether nuclear-driven (in)stability positively or negatively affected American interests. That is, it would be necessary to show how these changes would affect America’s ability to achieve other objectives and interests. Several studies examine U.S. nonproliferation tools, but more fine-grained analyses addressing the effectiveness of individual and combined policy levers are needed.125 It would be informative, for instance, for research to disentangle whether a U.S. security commitment is sufficient to provide leverage (supporting deep engagement), or if it must be coupled with a global/regional institutional order and specific regime types (supporting liberal internationalism), or a strong commitment to use force against potential proliferators (supporting conservative primacy).

A second example draws from the legitimacy axis of the debate. The different grand-strategic positions disagree on whether international legitimacy matters in determining whether U.S. strategies, such as troop deployments and the use of military force, are likely to be stabilizing or destabilizing (or have no effect on stability either way). Liberal internationalism holds that the use of American military force abroad promotes stability when the United States exercises self-restraint and adheres to international norms and the rules and processes of inclusive international institutions such as the U.N. Security Council. Conservative primacy, on the other hand, argues that U.S. military force can be carried out unilaterally and will command legitimacy among democracies so long as its exercise is consistent with liberal ends. For example, conservative primacy would predict that the U.S. failure to intervene in Syria after Bashar al-Assad’s use of chemical weapons in 2013 would undermine U.S. legitimacy and generate greater instability by inviting challenges to U.S. leadership. Alternatively, liberal internationalism would predict that unilateral U.S. efforts to roll back North Korean nuclear and missile achievements ought to promote instability by undermining alliances and provoking adversaries. Conservative primacy would expect the opposite result: that allies would be heartened by these measures and adversaries cowed. In each example, researchers can test the competing claims against international outcomes in terms of stability and public and elite opinion abroad as a measure of international legitimacy.

In sum, this article’s focus on why proponents prefer a given set of grand-strategic objectives and corresponding levers will allow future research to better assess the relative effectiveness of these objectives and levers for attaining U.S. interests. It is necessary not only to test individual relationships between tools and objectives, but also to assess how those relationships interact with one another to highlight the various trade-offs inherent in any grand strategy that attempts to establish priorities, balance competing demands, and bring a diverse set of policies into an overarching agenda. This is more demanding than narrow hypothesis-testing but has the potential to fill a critical gap between scholarship and policy and move us closer to the ideal of evidence-based policy.

Acknowledgements: For helpful discussions and suggestions, the authors would like to thank Michael Beckley, Stephen Brooks, Michael Desch, Eugene Gholz, Kelly Greenhill, Henry Nau, Jacqueline Hazelton, Alexander Lanoszka, Barry Posen, Miranda Priebe, Andrew Ross, Joshua Rovner, John Schuessler, Joshua Shifrinson, Nina Silove, William Wohlforth, the three anonymous reviewers, and the Texas National Security Review editors.

Paul C. Avey is assistant professor of political science at Virginia Tech.

Jonathan N. Markowitz is an assistant professor in the School of International Relations at the University of Southern California.

Robert J. Reardon is assistant professor of political science at North Carolina State University.