Fragmentation, institutional overlaps, and norm collisions are often seen as fundamental problems for the global (legal) order. Supposedly, they incite conflict and disorder. However, some scholars have also emphasised functional and normative advantages of the resulting institutional pluralism. We argue that the consequences of the increasing international institutional density are conditional on whether and how different norms, institutions, and authorities are coordinated. In distinction from the fragmentation framework in international law and the regime complexity framework in international relations, this introduction outlines an interface conflict framework that enables important insights into this question and guides the contributions assembled in this issue. It zooms in on the micro-level of conflict between actors that justify incompatible positional differences with reference to different international norms. In particular, the concept of interface conflicts allows studying the conditions under which overlaps and norm collisions become activated in conflicts as well as the ways in which such conflicts are handled. Foreshadowing the main findings of the contributions to this Special Issue, we hold that interface conflicts are neither inevitable nor unmanageable. Most importantly, it seems that, more often than not, conflicts stimulate cooperative forms of management and contribute to the building of inter-institutional order.

Institutional overlap emerges not only as an unintended by-product of purposive state action but also as its deliberate result. In two ways, this article expands existing research on the causes and consequences of institutional overlap. First, we establish that three different types of dissatisfaction may lead states to deliberately create institutional overlap: dissatisfaction with substantive norms and rules, dissatisfaction with decision-making rules and dissatisfaction with the institutional fit of an existing governance arrangement for a given cooperation problem. Each type of dissatisfaction triggers a distinct motivation for the creation of institutional overlap: to induce policy change, to increase influence on collective decision-making or to enhance governance effectiveness. Second, we demonstrate that whereas the motivation to induce policy change leads to interface conflicts, the motivations to increase influence on collective decision-making and to enhance governance effectiveness give rise to inter-institutional coordination. Three empirical case studies on global energy governance, the governance of global development banking and global environmental governance probe these analytical claims.

This article puts forward a constructivist-interpretivist approach to interface conflicts that emphasises how international actors articulate and problematise norm collisions in discursive and social interactions. Our approach is decidedly agency-oriented and follows the Special Issue’s interest in how interface conflicts play out at the micro-level. The article advances several theoretical and methodological propositions on how to identify norm collisions and the conditions under which they become the subject of international debate. Our argument on norm collisions, understood as situations in which actors perceive two norms as incompatible with each other, is threefold. First, we claim that agency matters to the analysis of the emergence, dynamics, management, and effects of norm collisions in international politics. Second, we propose to differentiate between dormant (subjectively perceived) and open norm collisions (intersubjectively shared). Third, we contend that the transition from dormant to open – which we term activation – depends on the existence of certain scope conditions concerning norm quality as well as changes in power structures and actor constellations. Empirically, we study norm collisions in the area of international drug control, presenting the field as one that contains several cases of dormant and open norm collisions, including those that constitute interface conflicts. For our in-depth analysis we have chosen the international discourse on coca leaf chewing. With this case, we not only seek to demonstrate the usefulness of our constructivist-interpretivist approach but also aim to explain under which conditions dormant norm collisions evolve into open collisions and even into interface conflicts.

When actors express conflicting views about the validity or scope of norms or rules in relation to other norms or rules in the international sphere, they often do so in the language of international law. This contribution argues that international law’s hermeneutic acts as a common language that cuts across spheres of authority and can thus serve as a conflict management tool for interface conflicts. Often, this entails resorting to an international court. While acknowledging that courts cannot provide permanent solutions to the underlying political conflict, I submit that court proceedings are interesting objects of study that promote our understanding of how international legal argument operates as a conflict management device. I distinguish three dimensions of common legal form, using the well-known EC–Hormones case as illustration: a procedural, argumentative, and substantive dimension. While previous scholarship has often focused exclusively on the substantive dimension, I argue that the other two dimensions are equally important. In concluding, I reflect on a possible explanation as to why actors are disposed to resort to international legal argument even if this is unlikely to result in a final solution: there is a specific authority claim attached to international law qua law.

Legal multiplicity in the global realm, and the interface conflicts that ensue from it, are widely thought to have a destabilising effect, blocking the path towards a more integrated and perhaps constitutionalised global order. While this diagnosis may appear plausible if interface conflicts are seen as snapshots and rivalrous institutions as the main actors, it is less convincing if we regard these conflicts as part of social processes of contestation that define the relations between different norms over time. It is also less plausible if actors with other orientations – norm irritation or navigation – are taken into view. This article works towards a more encompassing account, both temporally and as regards actor orientations. It uses two case studies of conflicts at the interface between economic governance and human rights to probe the plausibility of its conjectures. Both cases appear as instances of prolonged norm contestation which, despite continued irresolution of the underlying conflicts as a matter of law, have resulted in a significant reorientation and (partial) consolidation around new interpretations. This suggests that interface conflicts, rather than destabilising the rule of law, may also open a pathway for change in the otherwise rigid structure of the international legal order

We analyse conflicts over norms and institutions in internet governance. In this emerging field, dispute settlement is less institutionalised and conflicts take place at a foundational level. Internet governance features two competing spheres of authority characterised by fundamentally diverging social purposes: A more consolidated liberal sphere emphasises a limited role of the state, private and multistakeholder governance and freedom of speech. A sovereigntist challenger sphere emphasises state control, intergovernmentalism and push against the preponderance of Western institutions and private actors. We trace the activation and evolution of conflict between these spheres with regard to norms and institutions in four instances: the World Summit on the Information Society (WSIS), the World Conference on International Telecommunications (WCIT-12), the fifth session of the United Nations Group of Governmental Experts (UNGGE) and the Budapest Convention of the Council of Europe. We observe intense norm collisions, and strategic attempts at competitive regime creation and regime shifting towards intergovernmental structures by the sovereigntist sphere. Despite these aggressive attempts at creating new institutions and norms, the existing internet governance order is still in place. Hence, authority conflicts in global internet governance do not necessarily lead to fragmentation.

This article traces recent changes of the practices and justifications of the use of force in intervention, in the context of African security governance, highlighting how these changes interact with norm transformations at the scale of the global order. In doing so, it conveys how a long-standing pattern of norm contestation between international and African actors over external intervention vs sovereignty, has started to give way to a mutually accepted division of labour. After 9/11, the paradigm of liberal interventionism has been incrementally replaced by the framework of stabilisation, with a re-prioritisation of sovereigntist agendas. This has increased collaboration between international and African actors, specifically prompting the United Nations and the African Union to divide tasks of mandating and enforcement, thereby increasing inter-institutional ‘order’. This consensus, however, far from signifying wider compliance with ‘liberal ordering’ principles, rather indicates the need to revisit central assumptions of the International Relations norm diffusion literature. While the latter emphasises the diffusion of ‘good’ international norms, especially pertaining to human rights and democratisation, the growing consensus on ‘intervention as stabilisation’ instead exposes how post-9/11 justifications of practices that carry the potential to downsize the scope of such norms, are starting to resonate across international, regional and national sites of policy and practice.

The After Fragmentation special issue unites political science conversations about regime complexity with legal/normative conversations about global constitutionalism through a focus on the generation and resolution of interface conflicts, defined as moments when overlapping elements or rule incompatibilities generate actual conflicts. Yet scholars choosing among these two perspectives actually have different objectives. After reviewing the two literatures, I argue that this special issue is closer to the global constitutionalism perspective, which generally seeks legitimated order. By contrast, the regime complexity literature asks how does the fact that global governance is spread across multiple institutions in itself shape cooperation politics. Investigating what it means to get ‘beyond fragmentation’, I suggest that the potential or actuality of rule conflicts is not necessarily a problem because conflicts are a normal and even salutary aspect of politics. If conflict is not the concern, then what should we be worrying about? Both perspectives, I argue, are amoral because they normalise and help justify an international order where responsibility is spread across institutions, promoting order while failing to address fundamental problems affecting people and the world. In this respect, resolving rule conflicts does not get us beyond fragmentation.

The contributions in the volume do a fine job of recounting the sites and modes of unravelling meaty issue-area ‘interface conflicts’ and studying their diverse implications. I have sought to consciously read these contestations here from the broader perspective of the global South. My overall plea is for more politics and not less when it comes to studying ‘interface conflicts’ and norm contestations. What this translates into is to embed the technicalities of norm conflicts in the backdrop of more fully fleshed out political currents and contexts. Methodologically speaking, while sympathetic to the process-driven agential micro-constructivist approach to studying these ‘interface conflicts’, I argue that ‘internalist’ accounts of perceptions must ideally tap on insiders to arrive at a richer appreciation of the anxieties and hopes surrounding particular norm contestations in specific issue-areas.