The liberal approach: cooperation, constraint, and mutual payoffs

In her recent book on international courts, Leslie Johns provides a clear summary of the cooperative view of international law and politics. She says:

Johns identifies a real-world need for inter-governmental cooperation and suggests that better outcomes are possible when governments stay within cooperative and legalized parameters. The bounds of appropriate behavior are defined by the international laws, rules, and courts that governments agree upon. The reward for complying is a share of the ‘benefits of cooperation’.

The idea of cooperation is at the heart of the liberal perspective in IR. It is traceable through the long history of state-of-nature thinking in liberal political theory that interprets political institutions as a consequence of free-will, but also can be seen to originate for IR scholarship in the rise of rationalist IR analysis in the 1970s and 1980s. The turn to liberal rationalism as framework for describing international politics and institutions brought with it the idea that ‘international institutions constituted mutually beneficial arrangements’ for governments.Footnote ¹¹ Under the influence of the ‘classically liberal argument of economists about individuals and firms engaging in mutually beneficial exchanges’,Footnote ¹² IR liberals constructed a school of research centered on the twin goals of identifying why governments sometimes choose cooperation over unilateralism and encouraging them to do so more often.Footnote ¹³

There are two ways in which liberal theory sees international law as essentially cooperative: in its founding and in its operation. Both follow from the rationalist assumption that states are self-regarding units that have the free will to advance their goals using the tools available to them, and together they end up morphing into the substantive claim that law is in fact consensual and mutually beneficial.

Cooperation appears first in the process by which governments negotiate, agree on, and ratify treaties, rules, and agreements. Global governance institutions are produced when negotiations result in agreements. The failure to agree leaves an empty place in the web of international governance, a space in which governments retain the full autonomy that is understood as their default condition.Footnote ¹⁴ Barbara Koremenos, for instance, analyzes international agreements as devices that help states overcome certain obstacles to cooperation such as cheating, monitoring problems, uncertainty, and asymmetry.Footnote ¹⁵ For her, ‘legalization’ is terminologically interchangeable with ‘cooperation’ – her goal is to understand how agreements are ‘affected by the particular characteristics of the actors cooperating’, and her data on legal agreements is a subset of broader ‘international cooperation data sets’.Footnote ¹⁶

Second, governments are said to be cooperating with each other when they choose to comply with a rule rather than to violate it. This opportunity to choose comes up frequently because there are many international obligations impose upon government decisions. The potential dataset of compliance decisions is therefore very large and behavioralist scholars routinely code compliance as cooperation and violation as non-cooperation.Footnote ¹⁷ Leslie Johns says ‘legal regimes are designed with an eye to both enhancing cooperation today among members of the regime and ensuring that these states cooperate in the future by remaining members of the regime’.Footnote ¹⁸ For Andrew Guzman, international law can be said to ‘matter’ – that is, to have an effect – when states choose to follow it.Footnote ¹⁹ This implies of course that they could also choose not to, and so Guzman's ‘theory’ of how international law works aims to understand how and when governments make the choice to comply. For Guzman, deference to the law is the same as cooperation.

In IR debates between realists and liberals in the 1980s and 1990s, the cooperation assumption served as a dividing line. Arthur Stein summarized the scholarly split in 2008 in the following way: ‘Realists after all focus on conflict and minimize the prospect for, and the nature of, international cooperation…. [while liberals] focused on the cooperation that underlay the new post-Second World War international arrangements’.Footnote ²⁰ This common way of describing the difference between realism and liberalism highlights their disagreement over the likelihood that ‘power’ can indeed be replaced by ‘cooperation’ in inter-governmental relations. To see world politics in terms of cooperation among governments made one a ‘liberal’; to see it in terms of power politics made one a ‘realist’. This disciplinary self-definition put cooperation and law together under the heading of Liberalism, and power and conflict together on the opposite side as Realism. With that, the dichotomy between cooperation and power was further entrenched.

The payoff to international cooperation, according to IR liberals, is that it promises better outcomes than those that follow from non-cooperation. This begins as an assumption, deduced from the premises of liberal theory, but it quickly becomes a substantive claim about international politics that leads to a policy preference in favor of rule-following. The logic follows like this: when states are modeled as choosing to cooperate through law, liberal theory infers that they are doing so because they see some benefit from it; without the promise of a benefit they would presumably choose some other option – this is the core of the assumption of rationality in liberal IR theory. Thus, the existence of private benefits can be deduced from the behavioral observation that governments are engaging in the practices of ‘cooperative’ international law. Trade treaties, for instance, are assumed to be good for both sides because no party would agree if it thought the deal harmed its interests. Issues of distribution and inequality arise in this framework as questions about how the gains that come from cooperation are shared. The debate about absolute-vs.-relative gains focuses on the division of gains between the ‘cooperation’ partners whereas debates about the domestic effects of global ‘cooperation’ focus on how gains are distributed within a state or society.Footnote ²¹ The existence of an international agreement is taken as sufficient evidence proving that its parties expected it to benefit from it.

The presumed cooperative nature of international law is evident when liberals suggest that the payoff is independent of the substantive content of the rules. A rules-based system is thought to be desirable in itself regardless of the content of the rules. A functioning legal system is assumed to produce generalized benefits for society and so is a good in itself. It is not necessary to ask about the details of the actual rules that make up the system, since the normative value of the system is provided by the ‘rules-based system’ itself. Michael Mastanduno illustrates this view by drawing on John Ikenberry's work:

Once international institutions are assumed to be founded on consensual membership, their existence is enough to confirm that they must be producing benefits for their members, otherwise their ‘rational’ members would not have consented to them. By logical deduction, liberal theory establishes that international institutions serve the common good. This conclusion is reached without looking at the specific content of the rules and institutions in question – it is ‘content-independent’ in the sense used by Samantha Besson.Footnote ²³

The joint assumption of rationality and mutual benefits is not merely an analytic device to simplify a complex reality. It flows through liberal analysis to become its normative and policy output; it acts as both assumption and conclusion. It feeds the liberal internationalist interpretation of American power and its claim to progress and development in world order after World War II.Footnote ²⁴ It underpins the belief that the answer to global problems, from pollution to corruption to genocide, is a ‘stronger endorsement of the institutions of international law’.Footnote ²⁵ The UN, NATO, and the WTO, are said to be examples of global cooperation in practice: the United Nations constitutes the ‘guardians of the common good’Footnote ²⁶; NATO is a ‘pool of partners who… by and large share fundamental values’ of cooperative securityFootnote ²⁷; and the WTO is the ‘embodiment of an integrated, peaceful world’ whose success ‘will serve us all well’.Footnote ²⁸ Together, these and other institutions are said form a social system among the nations that are ‘capable of rising above self-interested passions and entering into accord with other similarly constituted peoples for the sake of the general good – a common peace’.Footnote ²⁹ Max Boot accuses critics of global governance of ‘implacable hostility to international cooperation’.Footnote ³⁰ The existence of international institutions is interpreted as evidence of that cooperation is taking place.

Moreover, liberal internationalists have interpreted the post-WWII period of American hegemony as ‘cooperative’ on the grounds that the subordinate states have consented to the institutions of the post-WWII order. They participated in the negotiation of these institutions and they make an informed choice when they comply with them. This, according to John Ikenberry, is ‘a hierarchical order built around political bargains, diffuse reciprocity, provision of public goods, and mutually agreeable institutions and working relationships’.Footnote ³¹ It has ‘several features’ that ‘give it a more consensual and agreed-upon character than imperial systems’. Subordinate states consent to ‘supporting and abiding by agreed-upon rules and institutions’ he says because these generate benefits that are shared among the players.Footnote ³²

Josh Rogin merges a defense of legal institutions with his defense of human decency and good governance, assuming that the three are of a piece: ‘For too long’, he says, ‘Western democracies have taken a laissez-faire approach to defending the rules of rules-based institutions, while authoritarian regimes work to shape them to do their bidding. Solving that problem is crucial to winning the grand strategic competition and preserving our security, prosperity and freedom’.Footnote ³³ In a similar vein, Ikenberry makes grand historical claims about the benefits for human welfare of this ‘cooperative’ legal frame for global affairs. He says ‘International order is manifest in the settled rules and arrangements between states that define and guide their interaction. War and upheaval among states – that is, disorder – is turned into order when stable rules and arrangements are established by agreement, imposition, or otherwise’.Footnote ³⁴ In such a world, there are no losers from international legal agreements (except those who would deny international rules their appropriate power). Everybody wins.

The cooperative model of law implies a view of law as a constraint on state freedom rather than as a resource that empowers actors. International law is said to limit governments' scope of action and foreclose some options which otherwise would open to them. Koremenos says legalization is ‘a particular kind of institutional design – one that imposes international legal constraints on states’.Footnote ³⁵ The constraint of law, familiar from liberal political theory, is compatible with state sovereignty because both are assumed to begin with state consent.Footnote ³⁶ As John Ikenberry says, ‘a state bargains away some of its policy autonomy in order to get other states to operate in more predictable and desirable ways – all of it made credible through institutionalized agreements’.Footnote ³⁷ Legal obligations are said to be normatively preferable to political constraints. Adam Bower says ‘law is typically held to be more technocratic and impartial in contrast to an unregulated political realm in which material power is expected to dominate’.Footnote ³⁸ If law constrains everyone equally in the service of the common good it is hard to see why governments compete for influence to define the rules. Strong governments have long known that control over international rules is a source of power; it is part of the appeal of being a hegemon.Footnote ³⁹ This suggests that law is not a neutral, technocratic, constraint upon all; it is a useful device and entangled with the politics of those who use it.

Liberal internationalists see the distinction between the legal and political realms as crucial for modern global governance. Shannon Fyfe notes ‘the great promise of international institutions is that they could bring all peoples under the rule of law where rights are protected regardless of where one comes from’.Footnote ⁴⁰ Karen Alter suggests the split began around the end of the 19^th century and was institutionalized through the 20^th century: ‘the Hague Peace Conferences were moments for legal idealists to crystalize their bold vision of subordinating power politics to an international rule of law’.Footnote ⁴¹ Anne-Marie Burley used the separation of law from politics as a feature by which liberal states are identified: ‘Courts within this [liberal] zone evaluate and apply the domestic law of foreign states in accordance with general pluralist principles of mutual respect and interest-balancing. Nonliberal states, by contrast, operate in a “zone of politics”, in which domestic courts either play no role in the resolution of transnational disputes or allow themselves to be guided by the political branches’.Footnote ⁴² Where the principle of legal supremacy is respected, legal institutions are insulated from political influence and are thus empowered to issue rulings that reflect legal rather than political considerations.

This vision of the rule of law imagines a social order in which the legal system constrains the political. Liberal legal theory identifies the legal realm as a domain of consensual cooperation in pursuit of personal and mutual gains. This is distinct from the domain of politics, which is understood as a realm in which power is used to gain advantage. The liberal idea of the rule of law imagines a social system built upon legal control over politics. Leslie Vinjamuri and Jack Snyder define the two in ideal-type form: ‘politics’ relates to ‘bargaining behavior based on power’ whereas ‘law’ is characterized by ‘binding and authoritative rule-making, rule-following, and rule-enforcing behavior’.Footnote ⁴³ Politics operates from ‘power, interest, prudence, and strategic interaction in light of expected outcomes’ and law ‘proceeds within the logic of a system of rules’.Footnote ⁴⁴ They set out these two as distinct institutions or logics in a conceptual sense but their empirical analysis aims to show how they interlace. Andrea Bianchi says that ‘legal control over politics is a highly powerful notion in the collective imaginary’Footnote ⁴⁵ and it is widely proposed as a progressive accomplishment of modern times, replacing power with rules.

Thus, liberal theory generates the conclusion that compliance with international law is good for everyone: It produces both private and collective benefits. Private benefits are inferred from the behavioral observation that states are choosing to cooperate in legal institutions – if there were no private benefits they would presumably choose to do something else; and collective benefits come out of the existence of a stable, rules-based environment that is apparently good for all. The dominance of law over politics in liberal theory is thus understood to be good for everyone, and everyone is thought to benefit from increasing compliance with international law.

This leads liberals to the conclusion that enhancing compliance is a normatively worthy goal. Leslie Johns is explicit about this, as she says that ‘a key premise’ of her book ‘is that policy-makers can and should design institutions to facilitate cooperation’.Footnote ⁴⁶ The head of the Rule of Law unit in the United Nations said recently ‘the rule of law builds peace, contributes to sustainable development, and protects human rights’.Footnote ⁴⁷ Cooperation is understood as beneficial – politically and normatively – and international law comes to look like a generalized good, all winners and no losers.Footnote ⁴⁸

To recap: liberal political theory posits that international law represents a consensual set of constraints on state behavior. It produces a stable decision environment that is beneficial for all actors in the system. The legal system knits together the mutual interests of states into a structure that channels political choices within legitimate limits. Sustained by the ideological commitment to a ‘harmony of interests’, the liberal approach sees the rules and institutions of international law as a turn away from the power and coercion of politics. Liberalism ‘taps into the promise of the end of politics’ that ‘promises to free us from the contingencies and uncertainties of political debates and policy choices’.Footnote ⁴⁹ Governments that follow international law are understood to be acting as good international citizens, ‘cooperating’ with others, and enabling the achievement of collective goals, whereas those that violate international law are cast as ‘rogue’ states, self-interested, and anti-social.

The political approach: winners, losers, power, and tradeoffs

An alternative to the liberal worldview is available and it starts by assuming that people's preferences are in conflict with each other rather than in harmony. This alternative premise leads to a different line of research questions, a different interpretation of history, and a different set of policy prescriptions than the cooperation model. It sees law and governance as political engagements upon conflicting interests rather than as consensual arrangements founded in mutual benefit. It disputes the liberal effort to separate legal from political domains as a conceptual, empirical, and political matter. It identifies law as empowering as well as constraining, and so directs scholars to ask about who is being empowered or constrained and in relation to whom.

The work of expressing an alternative to the liberal approach is complicated by the implausible straw targets often used by liberal internationalists to contrast with their arguments. These invoke chaos, anarchy, or constant war, a world without any rules at all. Anne-Marie Slaughter suggests the alternative to liberal internationalism is the ‘return to anarchy’ in international affairs.Footnote ⁵⁰ Terry Halliday and Greg Shaffer see ‘transnational legal order’ as making ‘some order out of chaos, anarchy, unpredictability, or irregularity’.Footnote ⁵¹ John Ikenberry contrasts the legalized order that emerges from ‘stable rules and arrangements… established by agreement’ with ‘war and upheaval – that is, disorder’.Footnote ⁵² Reaching further back, Lassa Oppenheim aspired to the ‘ultimate victory of international law over international anarchy’.Footnote ⁵³ These are not well thought-out alternatives to legalization.

If the alternative to international law is anarchy, chaos, war, and upheaval, then it is easy to make an emotive case that law should be defended at all costs. But these antinomies lack a connection to reality. Social contract theory in the liberal tradition – Hobbes and Locke for instance – has always relied on the imagined pathologies of the pre-contract world to make its case. It is a bit fantastical to defend the existing body international law and institutions on the grounds that a hypothetical world without any law or institutions would be worse. It is akin defending Hayekian monetary policy on the grounds that it's better than a world where money had never been invented – that may be true but it is hardly the most relevant comparison. In addition, the assumption that today's international law resolves problems better than ‘politics’ would, or better than Russia or China would, presumes the thing that we need to know: what are the actual effects of following international law today, and how does this differ from following other interests?

A political approach toward international law begins by recognizing that law is written to advance certain interests at the expense of others. And global governance involves imposing outcomes on people, to the benefit of some and at the expense of others. It takes sides among competing claims and requires that some interests win whereas others lose. For instance, a schedule of trade tariffs favors some industries at the expense of others and allocates costs and benefits among produces, consumers, governments, and others; rules on taxation, capital mobility, and secrecy combine into a system of penalties and incentives that affect different people differently; various schemes to prevent COVID-19 spread or global warming impose costs and offer gains in unequal ways across classes, sectors, regions, and people. Global governance is no different than domestic governance in this way. Governance through law is one technology by which tradeoffs are imposed; others include markets, agenda-setting, and violence. Scholarship on international law and politics seeks in part to understand global governance through law and so needs to start with an intellectual framing of law and politics that makes this possible.

In some sense this is uncontroversial. Things could hardly be otherwise: by making some things legal and others illegal, law distributes responsibilities and rights among members of a community depending on their relationship to legality. This starting premise directs attention immediately to the question of whose interests are being advanced at whose expense. It points scholars to research questions that recognize competition among interests: which interests are encoded in the law and who is empowered by it? Whose interests are not in the law and what happens to those people? How does the application of the law affect the welfare of both the ‘winners’ and the ‘losers’? Daniel Nexon offers a hint in this direction when he observes that ‘for many who live outside its core, the liberal international order was never terribly liberal nor much of an order’Footnote ⁵⁴ – global governance looks different to different people according to whether it is advancing their interests or someone else's. This insight can be the start of a broad shift in how we assess the effects of international institutions and rules.

The difference is evident in Monica Hakimi's recent analysis of the politics of international law. She sees two versions of the ‘cooperation thesis’ in legal scholarship. There is a weak variant, which exists in the claim that international legalization is a step toward shared goals of peaceful dispute resolution, and a strong variant, which holds that ‘that defusing conflict is both a standalone goal and a means for achieving many other shared goals – on the economy, the environment, and so on’.Footnote ⁵⁵ The first sees dispute resolution through law as a form of cooperation and the second sees cooperative law as the path to a rules-based global social order with generalized benefits. Hakimi's complaint is that both marginalize political disagreement, with results that are counter-empirical and politically undesirable. They ‘assume that conflict impedes cooperation and is a problem for international law to overcome’Footnote ⁵⁶ and that international law provides a solution for political disagreements.

Hakimi argues that a better path, as both an empirical claim and a research premise, is to assume that conflict and cooperation are symbiotic in international law and in institutions more generally. ‘Even as international law enables global actors to work past their differences and toward shared ends, it also enables them to hone in on these differences and disagree – at times fiercely and without resolution…. Rather than foster cooperation at the expense of conflict, international law fosters both simultaneously’.Footnote ⁵⁷

Hakimi suggests that we see international law as a device to ‘facilitate real-world conflicts’ as much as it ‘facilitates real-world collaborations’.Footnote ⁵⁸ Down this road we find research that attends to the differences in opinion or interests that make up the political conflicts carried on through legalization and legal forms. As illustration, she uses the Libya 2011 intervention to see how international laws on war ‘served initially to curb and then to inflame a conflict’.Footnote ⁵⁹ The legal framework of jus ad bellum dissuaded France and the UK from intervening in Libya on their own, but once the Arab League asked the Security Council to authorize military action the valence of these laws reversed and they become a powerful force in support of military an intervention. She also documents that once the Council authorized force, the USA decided there was a need for ‘a broader mandate and more aggressive military strategy than others had been contemplating’.Footnote ⁶⁰ The Council's capacity to enable war is ‘hiding in plain sight’Footnote ⁶¹ and deep disagreements over how it should be used and against whom will not be erased by closer reading of legal texts or by further legalization.

Abe Newman and Elliot Posner make a similar point in their analysis of soft law and international governance. They aim to remind scholars that soft law is contentious precisely because it has the potential to govern and regularize social behavior.Footnote ⁶² As new rules are advanced, legitimized, interpreted, and applied, they are used as resources to ‘disrupt domestic political contests in’ favor of some interest group and at the expense of others. This cannot be captured by models of shared goals and coordination around focal points that imagine norms and rules as ‘quick means to promote cooperation based on mutual interests’ and to tame power.Footnote ⁶³ It misses what the actors already know: ‘the politics of institutions is an ongoing struggle’ among incommensurate interests.Footnote ⁶⁴

Arjun Chowdhury's contribution to the literature on weak states and state-formation begins from a similar premise. He reminds readers that the typical model of the modern state is that it ‘must monopolize organized violence and provide a basic level of services. If the state is to have the good effects said to justify it, the central authority must choose to protect the population and provide it services, and the population must choose to disarm and pay taxes’.Footnote ⁶⁵ This frames a state as a matter of choice, an exchange between population and government and imagines that a stable government arises when each side gets something that it values in exchange for willingly giving up something slightly less important. It's a good deal for all sides: the public gets protection and services and the state gets taxes and loyalty, whether in a democratic or authoritarian setting. Chowdhury makes a subtle change in this framework by recognizing the implicit role of ‘outside options’. Of authoritarian systems, he says ‘the population does not choose to live under tyranny; to say they “cooperate” is absurd’. It is more accurate to say ‘that they are unwilling or unable to defect – for example, because they are unable to coordinate a rebellion’.Footnote ⁶⁶ The cooperation thesis in state-formation interprets stability as an equilibrium of interests between population and government, but Chowdhury reminds us that this only makes sense if the public has an exit option that would allow them to express their interests when they diverge from those of the state. In practice, that option is foreclosed by the government – indeed, ‘exit’ is ruled out by the very definition of ‘government’ with its monopoly on violence and control over rule-making authority. Scholars who overlook the gatekeepers of exit will tricked into the illusion of consensus. Lloyd Gruber made a similar point regarding the implicit role of ‘go-it-alone’ power in the original NAFTA negotiations: liberal accounts of consent in trade negotiation risks overlooking the influence of unequally distributed exit options.Footnote ⁶⁷ Chowdhury argues that state-formation theory has made a similar mistake: the cooperative model is inadequate for explaining the proliferation of weak states.

These scholars represent a disparate strand in an emerging movement in the study of international politics that sees international law and regimes as places of contestation rather than as cooperative solutions to shared problems. This applies to formal institutions such as the UN Security Council and also informal social institutions including international law and international norms. It also reminds scholars of the importance of disaggregating the state and mapping winners and losers in both substate and transnational groups. This is an empirical movement that looks first at the real-world effects of international governance institutions and at their ‘lived experience’.

Contrary to Lassa Oppenheim, whose ambition mentioned above was to see the triumph of law over politics, the political approach does not aim to separate the ‘legal’ from the ‘political’. Instead, it begins from the premise that the two are mutually implicated. Rather than compare existing law to ‘no law’ or anarchy, it aims to compare one set of rules or institutions against other plausible sets according to their effects in the world.

This is the starting point for a wide range of scholarship on law and politics that includes variants of Marxism, critical legal studies, legal pragmatism, legal realism, and practice theory.Footnote ⁶⁸ Each of these is involved in debates that are beyond the goals of this paper – my more modest interest is in showing the broad differences between a liberal approach to international law and a political one, as they are manifested in scholarship on global governance. Rather than strive to isolate legal from political forces, the alternative intellectual tradition aligned with legal realism and pragmatism provides tools for understanding the politicization of international law and the legalization of international politics. This is both a conceptual and an empirical contribution, and by following it scholars of global governance end up with a different set of research questions and methods as well as different policy conclusions. The political approach is not new – it puts to work familiar ideas about law, power, and politics in service of better understanding the controversies around international legal institutions and the international rule of law more broadly.

Implications for methods, interpretation, and policy

The recognition that law encodes tradeoffs among political goals leads to three implications for research on international law and politics.

First, the rule of law ideal, consisting of the neutral application of rules across cases, is not politically neutral. International law is necessarily partial to some goals and opposed to others and it will therefore have unequal effects on its constituents. The rose-colored glasses that are often used to interpret the world of international law lead scholars to assume that global governance enacts the best ideals of humanity, universally shared and therefore uncontroversial. Darryl Robinson adopts this view in his analysis of international criminal law (ICL): ‘I believe that cosmopolitanism resonates with the aspirations of ICL: a concern for human beings that extends beyond borders; a willingness to embrace alternative governance structures to supplement state structures; and inclusiveness of the concerns of the “international community as a whole”’.Footnote ⁶⁹ Shashi Tharoor has called the United Nations ‘the best hope the world currently has’ for its problems because it ‘brings all the countries of the world together to pursue collectively the security and welfare so essential to our common humanity’.Footnote ⁷⁰ This is an ‘enchanted view’ of international law and governance.Footnote ⁷¹ Fernando Nuñez-Mietz assumes that international law is naturally morally good: ‘the content of much of international law is a reflection of shared understandings of what is morally right’.Footnote ⁷² To liberals, international law can seem like a magical machine that takes in hot controversies and feeds out cool, impartial solutions.

The limits of this view are easy to see. If one were to take the same assumption into the study of tax law, the results would be equally weak. As tax law creates categories for different kinds of income and wealth and it sets rules to govern how each is taxed, it draws lines around types of person or institution and taxes them differently. These are understood as political because they affect different interests differently, and they are fought over in legislatures and in the streets by the partisans of these interests. The law is politically productive in the sense that it creates inequalities which then present to individuals as incentives to get on one side or other of the law and gives rise to new terrains of political contestation.Footnote ⁷³ In the USA for instance, where religious institutions are not taxed, courts are required to monitor the distinction between religious and non-religious institutions so that the rule can be ‘correctly’ applied as various entities seek to be declared ‘religious’ for tax purposes.Footnote ⁷⁴ The social distinction between religious and non-religious is made into a legal distinction, governed by the state, with tax consequences. Tax law might be applied in a neutral manner in the sense that everyone is expected to follow the same rules equally but the effect of application is not neutral because the law works to the advantage of some over others. It cannot be apolitical.

International law can be seen in the same light. Depending on how it is used it could prioritize the interests of states over people, or powerful states over less powerful, or corporations over nature, or the opposite of these. It specifies which laws govern the Nepalese peacekeeper sent to Haiti by the United Nations and it regulates how a Haitian who suffers harm by that peacekeeper can seek compensation and from whom.Footnote ⁷⁵ It constrains some kinds of killing and while empowering others.Footnote ⁷⁶ And it could be written differently so that it would encompass different sets of winners and losers,Footnote ⁷⁷ just as tax law could. But it can't be written so that it benefits everyone.

Because international law reflects partial rather than universal interests, it is important to investigate which interests are served and which are denied. The empirical, pragmatist research agenda that I advocate in place of cooperation theory traces the actual distribution of welfare and power created by these rules or institutions.Footnote ⁷⁸ David Kennedy has pursued this work in connection with humanitarian action, motivated by the idea that ‘once we see international humanitarians as participants in global governance – as rulers – it seems impossible not to be attentive to the possible costs, as well as the benefits, of our work’.Footnote ⁷⁹ The simple assumptions of liberalism, of consent and mutual gains are bypassed. As David Lake says, ‘as a set of rules, international orders affect individuals and groups in different ways, and these actors pursue their interests to the extent of their abilities, including legitimating the rule of some foreign country or resisting that rule. International order is not simply Pareto-improving cooperation, as often theorized in international relations, but involves hard bargaining and winners and losers’.Footnote ⁸⁰

Second, because it has these political effects, international law is a powerful tool for governments and others and it has come to occupy an important place in their strategic behavior. States and activists invoke international law strategically with an eye on its potential to help them achieve their goals. It empowers governments, as well as constraining them. The instrumental use of law to advance interests is seen by some liberal theorists as the direct contradiction of the idea of the rule of law, but as a practice it is ubiquitous in IR. Brian Tamanaha argues against instrumentalism in his book Law as a Means to an End: Threat to the Rule of Law.Footnote ⁸¹ A similar complaint comes up around international courts. Shannon Fyfe, noted above, seeks to root out ‘impermissible political influence’ from the work of the ICC while allowing it the admittedly political goal of deterring or punishing perpetrators.Footnote ⁸² These complaints presume the separation of law from politics and they strive to keep each in its box.

A political approach to law recognizes that instrumentalism is an inescapable part of legalization. This is true of international law just as it is of domestic tax law. Countries bring cases to international tribunals when they believe that a legal judgment will help their political goals, as Australia did over Japanese whaling and the USA did at Nuremberg and governments do with self-referrals to the ICC.Footnote ⁸³ Contesting political disputes in legal form is the norm not an aberration. The turn to law, in the form of legal institutions, legal resources, and legal logics, is a political one, with characteristic effects on the shape of arguments, the roster of authorized actors, and the distribution of power and payoffs.Footnote ⁸⁴ ‘Law’, said Judith Shklar, ‘is a political instrument’Footnote ⁸⁵ and Martti Koskenniemi went on to say that every legal choice is a ‘politics of law’.Footnote ⁸⁶

The instrumentalization of legal resources for political purposes follows naturally from the idea of the rule of law, which elevates legal institutions to the authoritative position of deciding how things should go. A regime of legal supremacy directs actors to fight their fights in the language of law. This is not particularly controversial as a conceptual point – indeed, it sits inside much liberal analysis of law – but the methodological commitment to separating legal from political makes it harder to recognize and study.Footnote ⁸⁷ Bower says that the goal of legal discourse is to ‘shift the strategic terrain [between contending parties] such that the other arguments are no longer sustainable’.Footnote ⁸⁸ Even in a setting where courts are not available, legal argumentation is strategically powerful. David Luban identifies the expressive power of international prosecution as the main payoff to the ICC itself: ‘the most promising justification for international tribunals is their role in norm projection’.Footnote ⁸⁹ The court's function is in a sense ceremonial, showing the values of the international community in vivid color. This is political theater, deployed instrumentally in pursuit of what he sees as universal goals.

The widespread commitments to rule-of-law ideology in world affairs means that being seen as acting lawfully is politically powerful – it gives legitimacy to the state and its policy.Footnote ⁹⁰ These are valuable resources and we should expect actors to reach for them. The substance of international law will tilt in the direction of those with the capacity to invoke it, shape it, and apply it, that is to say: toward strong states rather than weak states or non-state actors.

The hope that law might be a weapon of the weak is widely shared among liberal scholars but it runs into empirical difficulty. Lee Seymour notes that the ICC prosecutor once declared ‘I believe in law as power for all; it is the ultimate weapon that the weak have against the strong’.Footnote ⁹¹ Adam Bower also sees the ICC as empowering weaker players relative to the USA.Footnote ⁹² Harold Koh recently outlined his vision of ‘law as resistance’ in his book on legal efforts to counter the Trump administration at home and abroad.Footnote ⁹³ To be sure, there are many instances where less powerful actors use the law to defend themselves against powerful states. Harold Koh's account of legalized resistance offers some success stories as does David Cole's similar book on domestic US constitutional issues, Engines of Liberty.Footnote ⁹⁴ But the capacity of law to serve the interests of the weak is minor compared to its more common function of serving the goals of those who control it. Since international law is authored by states and mainly developed, interpreted, and changed by strong states, its development over time tracks the changing interests of those governments. This is evident around the rules of self-defense in the law on the use of force, which evolved from its mid-20^th century origins as a ban on war into a more permissive regime that the USA and others now use to legitimize military operations under the headings of counterinsurgency, intervention, and targeted killing.Footnote ⁹⁵ Strong states have the capacity to shift the operative interpretation of international legal rules – this is baked into international legal theory and practice, as Tom Ruys notes that treaty interpretation must take into account ‘evolutions in the international security environment’ as it decides what is lawful and what isn't.Footnote ⁹⁶ Thomas Franck and W. Michael Reisman embedded this point in their grand theories of international law, offering great-power interests a prominent role as a formal source of legal change.Footnote ⁹⁷ With this in mind, we can comfortably predict that international legal development will follow the interests of the most powerful actors. This is not a weapon of the weak.

Finally, to declare that a government must ‘comply with international law’ is not politically neutral. It favors the political goals that are encoded in the rules, which may or may not be goals one actually wants to advance. This is important for foreign-policy scholars because compliance is widely endorsed by liberal internationalists as the most sensible policy choice – it is presented as self-evidently better for the individual, for its partners in legal arrangements, and for the whole idea of a rule of law system. It produces an image of non-compliance as anti-social, self-interested, and a signal of bad character on the part of a state. For instance, Mary Ellen O'Connell has said ‘given the nature of the problems we face in the world, …. any effort to weaken international law only serves to undermine the prospects for achieving an orderly world and progress toward fulfillment of humanity's shared goals, including prosperity’.Footnote ⁹⁸ Judith Shklar described this normative attitude under the label ‘legalism’.Footnote ⁹⁹ A government that wishes to be seen as a member of international society in good standing is encouraged to comply with the legal regime regardless of the content of the rule in question.

The utility of international law and institutions for powerful governments may help explain why the liberal approach to cooperation has remained so popular despite the problems identified in this paper. The history of liberal internationalism, and its place in the imaginative world of IR theory, is told well by Beate Jahn.Footnote ¹⁰⁰

The pro-compliance policy recommendation helps advance the interests that are encoded in international law. Once we understand these interests as partial rather than universal, the normative question regarding whether compliance is desirable or not is revealed to hinge on how we feel about the values of those partial interests. The normative issue is reopened for discussion, centered not on myths about the universal benefits of rules-based governance but instead on real-world assessments of the effects of specific rules on people with diverging interests.