by Ole Kristian Fauchald and André Nollkaemper (eds.). Oxford and Portland, Oregon: Hart Publishing, 2012. 382pp. Cloth $100. ISBN: 9781849462471.

Reviewed by Andreas von Staden, Department of Political Science, University of St. Gallen, Switzerland. Email: andreas.vonstaden [at]


The tremendous growth in the volume of international law and of different institutional sites for its interpretation and application, especially since the end of the Cold War, has raised the specter of the “fragmentation” of the international legal order. Against the background of the decentralized, issue-area-specific manner of the creation of international law and the lack of any centralized authority with competence to decide among competing interpretations of international legal norms, one potential source of problems, in the words of the International Law Commission (ILC) Study Group on the Fragmentation of International Law,

“is that such specialized law-making and institution-building tends to take place with relative ignorance of legislative and institutional activities in the adjoining fields and of the general principles and practices of international law. The result is conflicts between rules or rule-systems, deviating institutional practices and, possibly, the loss of an overall perspective on the law” (International Law Commission 2006 p.11).

While the legal pluralism that underpins fragmentation can have positive aspects—such as greater democratic legitimacy, enhanced responsiveness to issue-specific functional requirements, and the benefits of experimentation—it also threatens one of a legal system’s core values, coherence, and the values of predictability, legal security, and equal treatment that go with it (ibid.,p.248). As the ILC concluded,

“international law will need to operate within an area where the demands of coherence and reasonable pluralism will point in different directions. In order for it to do this successfully, increasing attention will have to be given to the collision of norms and regimes and the rules, methods and techniques for dealing with such collisions” (ibid.,p.249 [italics omitted]).

The edited volume by Ole Kristian Fauchald and André Nollkaemper here under review approaches the phenomenon of fragmentation specifically through the lens of the role of courts, both in furthering fragmentation as well as in countering it. While much recent work on fragmentation in international law deals with the effects of horizontal relationships between international legal regimes and the institutions that are part of it, Fauchald and Nollkaemper broaden the focus to include national courts as [*449] well, arguing in their introduction that “[e]ven more than fragmentation between different international legal regimes, the fragmentation caused by divergent national receptions of international law is a reflection of a more fundamental, multi-dimensional fragmentation of global society itself” (p.10). The main body of the book is accordingly divided into two parts, the first dealing with international courts and the second turning to the role of national courts. A conclusion—unfortunately not a standard in the world of edited volumes when it should be – draws together the findings of the individual chapters and highlights future research desiderata.

The section on international courts, comprising five chapters, begins with a contribution by Yuval Shany who discusses the probability that international courts will engage in “norm-harmonization” and “jurisdiction-regulation” efforts in furtherance of the unity of international law in light of the prioritized function that a given international court serves. Shany distinguishes three such functions: classic inter-state dispute settlement (exemplified by the International Court of Justice (ICJ)); sustaining cooperative relations in exchange-based regimes by adjusting underlying legal equilibria (his examples being the WTO Appellate Body (AB) and what is now known as the Court of Justice of the European Union (CJEU)); and the promotion of state compliance in the human rights and criminal law fields (e.g., the International Criminal Court (ICC) and the European Court of Human Rights (ECtHR)) (pp.19-20). Neither of these functions yields a privileged role for systemic considerations beyond the regime that provides the relevant court’s immediate environment, however. To the contrary, Shany comes to the conclusion that to promote the former, such “broader ‘systemic welfare’ interests must be legitimized through appeal to the more specialized interests of the specific regime and parties” (p.32).

The picture that emerges from the more empirically focused subsequent contributions remains mixed. Examining the reliance on the customary rules of treaty interpretation as codified in Articles 31-33 of the 1969 Vienna Convention on the Law of Treaties (VCLT) by WTO dispute settlement bodies, Lukasz Gruszczynski finds several instances where panels or the AB have, in his view, either relied too much on a purely textual approach (pp.41-46), thus sidelining a treaty’s object and purpose as key interpretive signposts (cp. Art. 31 (1) VCLT), or have marginalized WTO-external law (pp.46-52), despite the obligation codified in Article 31 (3) lit. c VCLT to take into account for purposes of interpretation “any relevant rules of international law applicable in the relations between the parties.” Still, Gruszczynski notes that, overall, such “deviations …. are not frequent” and have become even less so in recent WTO jurisprudence (p.56). It is in any event, not entirely clear what impact the use of rules of interpretation has on (de-) fragmentation. One does not have to be a Legal Realist to regard the hypothesis that “the use of the same methodological devices by different international tribunals … will lead to greater convergence in their interpretative results” (p.52) with skepticism. (A similar criticism applies to the editors’ conclusion that reliance [*450] on the VCLT rules in the interpretation of international legal materials by national courts will yield the same meaning that those materials have at the international level (pp.355-356)). Invoking interpretive rules and applying them in practice are two different things, and one and the same rule of interpretation can sometimes be relied on to justify divergent outcomes. This is one of the reasons why interpretation is generally seen as an art, not a science: Even with identical rules of interpretation, much still depends on the eye of the beholder.

Other chapters in this set address rules and mechanisms for the coordination of policy and jurisdiction to avoid conflicts between organizations in closely related issue areas (chapter 4, by Claus D. Zimmermann, on the interaction between WTO and the IMF in the fields of trade and monetary affairs); the constraints that a court’s self-perception as a regional court in the field of human rights can have on the use, and modification, of general rules of interpretation, despite their abstract attractiveness as alleged instruments of greater unity and coherence (chapter 6, by Ragnar Nordeide, on the ECtHR’s ultimately selective reliance on the rule of systemic interpretation); and the practice of some ad hoc arbitral tribunals to base their interpretations of bilateral investment treaty (BIT) provisions on previous awards that have dealt with comparable (“pari materia”) provisions in otherwise separate, independent and often later treaties than the one at issue in the proceedings before them (chapter 5, by Martins Paparinskis). Importantly, while showing the shortcomings in several of the proposed justifications for this approach, Paparinskis in the end finds that these attempts to impose unity in the face of diversity through such interpretive approaches have remained rare and have “not resulted in an underlying normative shift of the meta-rules” (p.113) on sources and interpretation: The existing “system may be far from perfect for ensuring fully harmonious development of law, but it accurately reflects the unified meta-rules on sources and interpretation and is precisely the kind of system that states have crafted over the last 50 years” (p.114). His contribution is one of the few that explicitly recognizes that the fragmentation within the international investment protection regime, illustrated by the universe of by now well over 2,500 BITs, has been a consequence of intentional design, not accident, a fact that should not fail to influence the interpretation of the terms of any specific BIT.

The eight chapters dealing with the role of national courts continue several thematic strands broached in the chapters on international courts. Jean d’Aspremont finds that reliance on the rule of systemic interpretation by national courts has the potential for fostering greater unity of international law, but may also contribute to fragmentation when domestic judges proceed on the basis of “contradictory systematizations of international law” (p.164). In any event, d’Aspremont argues, the application of the international rule of systemic interpretation often follows from the domestic principle that national laws should be interpreted, as far as possible, consistently with a state’s international obligations, which in turn requires that a state’s international obligations need to be put in relation to each other. Indeed, [*451] as Andreas R. Ziegler points out (chapter 14), it is this reliance on the widely adopted principle of consistent interpretation that has provided for the effectiveness of WTO law domestically in Switzerland, despite the absence of the recognition of a direct effect of WTO law. Antonios Tzanakopoulos (chapter 9), by contrast, shows how national courts have also resisted the authority of international law and its interpretations by international organizations by adopting a version of the German Federal Constitutional Court’s “Solange”-approach which makes deference to the international level dependent on basic rights protection comparable to that available at the national level. Here, domestic courts have provided incentives for their international counterparts to provide for greater legal unity by importing rights protection from the national level into their jurisprudence.

In addition to systemic interpretation, formal as well as informal transjudicial dialogue is often seen as a possible antidote to the fragmentation of international law. But while a rich theoretical landscape and extensive empirical evidence of communication between courts exist, the precise effects of this communication have remained ambiguous, not least because courts and their judges differ in the extent to which they acknowledge such cross-fertilization through explicit referencing of other courts’ case-law. In his case study of the jurisprudential stances taken by various courts on the acceptability of diplomatic assurances against torture in extradition proceedings, Antonios Constantinides finds that while transjudicial dialogue indeed takes place, the outcome is more one of “coherence in the sense of compatibility rather than perfect unity” (p.293). He also cautions that unity, while important, “should not be an end in itself nor the end of the story” (p.294). What emanates from much empirical research on the phenomenon of transjudicial dialogue, here and elsewhere, is also that there is great variety in the presence of engagements with other courts, “rang[ing] from in-depth, critical analysis to confused or selective citation to the complete absence of reference to the decisions of other jurisdictions” (p.257) (chapter 11, by Philippa Webb, on dialogue concerning immunities in human rights litigation).

Another recurrent finding that leads to the conclusion that the reception and application of international law by domestic courts will frequently tend to contribute to fragmentation is that such reception is almost necessarily conditioned by prevailing national politico-legal ideologies. Tor-Inge Harbro (chapter 8), for example, shows that the (limited) impact of the ECtHR’s proportionality analysis on domestic human rights jurisprudence in the UK and Norway is in part a reflection of the fact that such analysis is seen as inherently political and thus better undertaken by the elected branches of government (p.182). And in Japan, the application of international human rights provisions against racial discrimination (chapter 13, by Timothy Webster) has resulted in the odd situation that they are effectively enforced against private parties, despite denial of a direct effect between private parties, but not against the government, towards which the courts assume a deferential posture (p.319). And even where there is no national bias one way or the other, the [*452] fact that there are different interpretations available means that national courts that choose one of them inevitably at least maintain a given level of fragmentation. This appears to be the case with the Canadian courts’ interpretation of their jurisdictional competence to adjudge extraterritorial human rights violations (chapter 10, by Robert J. Currie and Hugh M. Kindred): Faced with a fragmented practice of interpreting jurisdictional rules in light of the growth of the conventional human rights regime, the Canadian courts preferred to stick to a traditional, mostly territory-based understanding of jurisdiction, a practice that itself, in the view of the authors, “reflects, even contributes, to fragmentation in the international law of jurisdiction” (p.243). If one adopts this lens, of course, then in legal areas that are undergoing change because some actors adopt new approaches and interpretations, subsequent decision-makers always also contribute to fragmentation, at least for the time being, because both maintaining traditional interpretations and adopting new ones fail, by themselves, to bring about unity, until all actors agree to either revert to the old approach or switch collectively to the same new one.

It is one of the book’s strengths that it provides ample empirical material on the various ways in which courts at both the national and the international levels contribute to fragmentation and defragmentation of international law as well as the techniques they employ. The dominant impression, supported largely by the editors’ own final comments, is that neither of the main techniques advocated to counter fragmentation – shared rules of interpretation and transjudicial dialogue – does so successfully. The rules of interpretation laid down in Arts. 31 and 32 VCLT, while frequently invoked, are themselves subject to different interpretations and applications in practice, leading Fauchald and Nollkaemper to conclude “that the Convention in itself is too open textured to be a significant force for the determination of processes of (de-)fragmentation, and that factors specific to the treaty regime, and the outlook of particular international courts, carry more weight” (p.347; see also p.357). Similarly, the patterns of communications among courts are too varied, both in terms of frequency and volume and with respect to effects, to permit general conclusions as to whether transjudicial dialogue is a force in the service of fragmentation or defragmentation (p.350). Ultimately, the value of the several case studies may be seen less in the answers they provide, but rather in the questions they raise for further research (pp.347, 350, 359, 363, 365).

While descriptively and empirically rich, the volume in the end also remains theoretically and methodologically thin, at least from the vantage point of scholars with a social science background. What is striking is the near-absence of references to the expansive judicial politics literature which could be relied on to generate hypotheses as to why courts at various levels of organization might be inclined or disinclined to engage in jurisprudential moves that either contribute to fragmentation or to defragmentation. Shany’s chapter is the most outspoken one in this regard when he points to the incentive structures that judges face, but he also stops short of elaborating in greater detail a judicial decision-making [*453] theory that would illuminate how and under what conditions these incentives operate to produce specific results. Greater engagement with theories that seek to explain, at a systemic level, the logic of fragmentation, or decision-making at the level of individual courts and judges, such as the well-known attitudinal, strategic choice, and historical institutionalist models, or approaches highlighting the role of judges’ audiences or national legal cultures, amongst others, would have been analytically promising here. As it stands, such theory-driven analytical research that seeks to explain, rather than merely describe, judicial behavior contributing either to fragmentation or to defragmentation, remains to be undertaken elsewhere, but the empirical material provided in this book should provide very useful data to commence such work.


International Law Commission. 2006. Fragmentation of International Law: Difficulties Arising from the Diversification and Expansion of International Law. Report of the Study Group of the International Law Commission, finalized by Martti Koskenniemi. UN Doc. A/CN.4/L.682 (April 13, 2006). Available at (accessed Sept. 12, 2012).

Copyright 2012 by the Author, Andreas von Staden.