I

There has not been much ‘internal’ theory of international law of late. Abstract examinations of the ‘binding force of international law’ ended in mid-century with the acknowledgement that the whole question was either a mystery – best relegated to the intrinsically mysterious realms of morality and natural law – or then had to be treated as a preface to psychological (‘feeling of obligation’) or sociological (what people actually do) enquiries. How does one argue about obligation in a morally agnostic world? One could perhaps excuse post-war German international lawyers grasping on to a moral vocabulary of world community and jus cogens. But cool-headed realists of different pedigrees (American, Scandinavian, also German) would rather prefer ‘scientific’ treatments of obligation by translating it either into a sentiment of being bound or the empirical fact of compliance. This would make law really a piece of psychology or sociology and put to question the point of the rites of a legal craft that appear inextricable from the mystique of its authority.

Something like this lay also behind the campaign by US political science departments in the 1980s and 1990s to initiate ‘interdisciplinary’ studies of international law. To overcome the blatantly unscientific antics of international law, they needed to be translated into empirical or rationalist languages of, say, ‘legitimacy’ or ‘compliance’ to enlist them more efficiently in the service of various (liberal or not-so-liberal) agendas to which those departments pay service. Not much remains of this campaign. Whatever they may have said, lawyers rarely saw the point of learning novel vocabularies of which they would no longer be the native speakers. ‘Interdisciplinarity’ seemed always to be less about collaboration than conquest, an attempt to grasp the law's normative voice by somebody else.

Brunnee and Toope have no overt interdisciplinary agenda. They situate themselves as international lawyers in the quintessentially juridical problematique of ‘obligation’. If they occasionally lapse into the political science language of ‘constructivism’, they do this to signal a wish to depart from the assumption that law is really just a confused type of psychology, sociology, or economics. This is a bold move that I wholly endorse. Whatever one thinks of the force of Lon Fuller's neo-naturalism – the principal inspiration behind the authors’ ‘interactional theory of international law’ – it does approach obligation by accepting that although law is embedded in social behaviour it is also irreducible to it. Had the authors contextualized Fuller's search for the legal ‘proprium’ in his efforts to provide a new consensus for post-realist American law in the 1950s in a value-oriented and purpose-oriented pragmatism (‘balancing’), they might have also found its limits in a context that is both pluralistic and weak in social cohesion. It is a shame that they have not engaged with Fuller's own tentative efforts to deal with international law or later critical engagements with it by Chayes, Koh, and others (Knop 2010, 65–70). Had they done this, they might have noticed how their own neo-naturalism embodies contested assumptions about the way the world is – assumptions embedded in equally contested normative abstractions about how it should be. This is the circle that ‘external’ theory with its empirical or rationalist ambitions seeks to break so as to provide policy-relevant predictions to those in powerful positions. Although a ‘Fullerian’ approach does provide an effective methodological critique of such pretensions, it is insufficient as a constructive alternative without making its own (contested) moral and evaluative assumptions explicit. Failure to do this (perhaps out of fear that decision-makers will anyway only listen to empirical or rationalist arguments) is the main weakness of the authors’ adaptation. Between calculation of costs and benefits and a ‘politics of law’, they have turned to long institutional discussions that somehow appear to suggest that there were never any choices to be made in the first place.

Brunnee and Toope have chosen Fuller as their guide to travel the heartland of the internal theory of legal obligation. This has led them to highlight such notions as ‘criteria of legality’ and ‘fidelity’ to the law that, whatever they mean, are not easily amenable to external analyses. Yet, it seems to me that they sometimes err on the side of the social or the psychological, particularly when they wish to provide ‘concrete guidance to lawyers and policy makers as they seek to understand and promote compliance with international law’. When they do this, their law tends to adopt the managerial position that no longer questions the need for ‘compliance’ and is only concerned over the ‘legitimacy’ of institutions to which everyone is assumed to have already committed. An analysis of legal obligation would not stop here, however. For it, dominant views about ‘compliance’ and ‘legitimacy’ would only point backwards to some (contested) normative assumptions about what there is to comply with or what ‘legitimacy’ might actually mean in the context where it is invoked. Such questions refer back from technical questions about the effectiveness of particular institutions or popular consensus to the normative frame within which these are articulated. A managerial or problem-solving law is always already committed to some formal (i.e. rule-like) purpose such as ‘clean environment’, ‘peace’, or ‘protection of human rights’ and only seeks optimal realization of these. Focus on obligation, again, would raise the question of the criterion from which to measure this: what ought ‘clean environment’ or ‘peace’ mean? Which of the competing understandings should prevail? How might they rank against different standards (‘economic development’ or ‘national security’, say)? That lawyers asking such questions are often felt by decision-makers as hopelessly counterproductive (‘finding a problem for every solution’) is a tangible illustration of the awkward appearance of the mystery of obligation in a technocratic process.

International law is not a very powerful instrument of governance. It revels in adversity, not in consensus. It deals with human relationships in a way that cannot be reduced to the purposes of an institution in which those relations are actualized. Fuller approaches this through his notion of ‘fidelity’. Something like it is also articulated in Immanuel Kant's ‘humility’ and Max Weber's ‘vocation’, expressions that give an elusive sense to such procedural values as fairness, openness to the claims of others, respect, inclusion, accountability, etc. These values do not look for the realization of some blueprint; they are about how members in a community should relate to each other. The institutional realization of such values of course varies, and is amenable to criticism from the perspective of those ideals themselves. But it is their urgency, the force with which failure to respect such standards is felt as a scandal in which we recognize the mystery of obligation.

II

I am sympathetic to the effort by Brunnee and Toope to bring ‘obligation’ to the centre of attention and their wish to test the institutional practices they have chosen to focus on, climate change, prevention of torture, use of force, against Fuller's criteria of obligation, and their embeddedness in the practices of legality. But the difficulty of this choice is illustrated in the authors’ occasional drift towards a kind of socio-psychological eclecticism. In their almost 100-page discussion of climate change, for example, the authors provide a thorough description of the intense diplomatic negotiations that, they argue, gave rise to a ‘community of practice’ within which reciprocal expectations and patterns of behaviour consolidated and attained de facto constraining force. Law, they thus conclude, had an effect on reality by working its magic slowly within the practices of which it forms a part. The description is realistic and appealing. But the choice of their standpoint – the aim to prove the law's effectiveness as a tool of governance – tends to turn it into a strategic instrument in the hands of the advocates of the climate change project. The objectives of this project have been set, the disagreements and difficulties laid out. All that remains for the law is to guide the process to its conclusion, into an effective climate change ‘regime’. The authors do pose the question of how the ‘criteria of legality’ in Fuller's natural law have been followed in the process. Have the negotiations been universal, the instruments clear and without contradictions and generative of predictable patterns of behaviour? Have the instruments been ‘congruent’ with practice? But in their wish to be ‘helpful’ to decision-makers, they tend to treat these values instrumentally; they are useful if they enhance the legitimacy of the institution.

The authors’ concept of law is deeply embedded in the social process of law making and application that they study. Indeed, they stress that the two processes should not be separated and warn against ‘undue faith in formal law making’. But the more they stress the close relationship between the law and the practices in which it participates, the less they are able to keep their eye on the mystery of obligation – that is to say, the way in which the very same law can also be used to create deviating understandings, reservations, and critiques regarding the climate change project itself. I am not worried about the absence of voice of the climate change sceptics. But I do worry about the authors’ lack of openness to the possibility that the institutional path chosen (a UN-drawn multilateral conference between State representatives) might itself be a part of the problem. The climate change chapter is so genuinely committed to its objectives and the smooth operation of its institutions that its law occasionally reads like a policy brief to the (Canadian?) delegation.

But of course the authors do not wish to make obligation disappear in this way. They know that a plausible legal vocabulary will have to show not only its realistic connection to the world of factuality but also its normative distance from that world. For example, they note that although ‘shared understandings’ play an important part in their account, obligation cannot be fully associated with them. After all (they might have added), such understandings may also be the effect of force, fraud, manipulation, ideology, or ignorance. Brunnee and Toope are sensitive to the power differentials and ideological forces in the world that make it impossible to accept any understanding or practice simply because it is there. They need a critical standpoint, which they receive from Lon Fuller's ‘criteria of legality’. But instead of examining the power these criteria have as criticisms of the climate change project or its manner of realization, they think of them in terms of their ability to produce the ‘sense of obligation’ – thus turning them into psychological techniques with which the participants may be geared to taking a positive attitude towards the settled goal. This is the problem with ‘legitimacy’ more generally, or shared understandings as criteria of the lawfulness of something: the state of affairs gives the criteria whereby that state of affairs should be judged. Whatever the outcome, this kind of (positivist) technique can only, as Herbert Marcuse long ago noted in one of the still best analyses of American political science, become part of the ideological consolidation of the status quo (Marcuse 1991, 115–16). The degree to which the frame itself is part of the problem is occluded by commitment to the chosen institutional path within it.

Similar types of considerations relate to the almost equally long chapter on the use of force. Brunnee and Toope begin their account by describing the shared understandings about the principles governing the use of force between states, moving from there to assessing those understandings in view of the ‘criteria of legality’, and finally asking whether the law as stated on this basis is broadly ‘congruent’ with official behaviour. The result is a fine assessment of the current state of the prohibition and the principal exceptions invoked to it. It is clearly correct to conclude that the traditional UN law has not been too much affected by the passions around the war on terror or by humanitarian intervention. Particularly useful here is the discussion of the way a fully self-judging rule on anticipatory action, such as included in the US Security Strategy of 2002, fails as a legal rule altogether. The discussion resembles the old critiques of unlimited opting-out provisions in arbitration treaties, or indeed the ‘autolimitation’ view of sovereignty of which Hersch Lauterpacht once pointed out that it contains no obligation at all:

This is a powerful point and would have provided a good opening for a further discussion of the mystery of obligation. On the one hand, it seems right to say that a rule that lets its addressees freely determine its content is somehow inconceivable as part of a legal institution. On the other hand, in most fields of international law (and especially in the use of force) the rules are both overtly indeterminate and riddled with large exceptions so that the constraint felt may actually be minimal. The conclusion might have been – especially from a Fullerian point of view – that it is lesser the law's substance than the fact that it is the law that is being invoked that is important. The description of the regime of force as a legal system would then not seem normatively innocent, whatever its content. Its ‘internal morality’ would call upon the actors to show – for the lack of a better word – ‘fidelity’ to each other. And all those legal values of fairness, honesty, transparency, non-retroactivity, responsibility would then provide the standard from which their actions should be assessed. Law's civilizing mission is less related to its substance than its status as law, and as such, its claim to be something other than the mere preferences of whoever is speaking, and hence also its obligation.

Law's power and attraction lie in its offering what appears a universal point of view, its ability to raise mere opinions onto a status of what is (universally) right (see further Koskenniemi 2004). And yet this universal standpoint constantly eludes us. Rules show themselves as mere interpretations, principles are challenged by equally powerful counter principles, etc. Even as claims about the law of force clash (as they of course constantly do), such claims are nevertheless united in their claiming a universal standpoint. Or to put this in another way, by recourse to law, the contestants agree that only a universal standpoint provides an acceptable basis for the exercise of institutional power (in the case the use of force) and thus the appropriate standards from which to hold it accountable. This particularity of the law – on which Fuller would have been in full agreement – might have led Brunnee and Toope, to examine what different types of ‘universal’ are being invoked in the arguments concerning the use of force today. What hierarchies and distributive choices are involved? Who is supposed to be competent to represent the universal? Behind the conventional law on the use of force, there is a whole world order, a system of empowering some and disempowering other institutions and dividing resources between human groups. Maintaining focus on ‘obligation’ would have linked the rules on the use of force to this normally invisible background. It would have raised Antigone's dilemma. Yes, this is binding law, but is ‘fidelity’ to it really called for?

III

Brunnee and Toope provide a dense analysis of international law as part of the diplomatic and political efforts to regulate climate change, to eradicate systematic torture, and to deal with the use of force among states. Their effort to maintain a distinctly legal tack on the materials is welcome. But notwithstanding their wish to keep distance between law and the diplomatic world they describe, they often tend to take this world too much for granted, its institutions and hierarchies as beyond critique. This is an invisible but practically inevitable outcome of their effort to use law to explain and to predict official behaviour – efforts that are quite incidental to law's main business to provide a standard of criticism of behaviour, including the behaviour of officials. Although (international) law is not only – perhaps not even predominantly – about helping authorities in the construction of normative-institutional frameworks of problem-solution and management, this is how it often appears in this work: a practice of legislating instrumental rules, and then managing them. In such a conception, ‘obligation’ always yields to the objectives of those in dominant positions.