In the last few decades, international legal theory has been characterized by heated debates on how different regimes of international and regional law functionally interrelate, the nature of international law as it is applied, and how international law relates to society. These debates are foundational because they concern the essence of how we think about international law, how it is enacted and practiced, and the extent to which it fulfils its stated aims.Footnote ¹ As international law has proliferated in scale and scope, its regulatory ambition has both expanded and deepened. At the same time, its different parts have also come into greater friction, prompting concerns about “fragmentation”Footnote ² or the rise of “international regime complexity”Footnote ³ as fundamental yet potentially disconcerting traits of international law today.

Within doctrinal legal scholarship, much energy has been devoted to how such normative frictions and overlaps should be functionally solved, ordered, or (re-)systematized.Footnote ⁴ Scholars of a more socio-legal orientation have critically explored how such dynamics can lead to politicization, as states on the one hand seek to optimize sovereign maneuverability through strategies such as forum shopping,Footnote ⁵ and on the other hand rights activists forge new normative linkages for strategic litigation.Footnote ⁶ Comparatively less attention, however, has been given to the more systematic affordances these types of normative interlinkages might ultimately bring about—in other words, their productive possibilities. Recent work on, for example, “inter-legality”Footnote ⁷ or “entanglement”Footnote ⁸ in international law suggests one possible direction for such a perspective, emphasizing, for instance, how repeated interactions across legal regimes may produce novel and oftentimes unforeseen normative effects.Footnote ⁹ To advance this scholarship, this special issue leverages another, related heuristic for thinking about how law interacts across normative scales and the relationship between international law and the socio-material world in a cohesive manner: Infrastructure.

Recent years have seen emerging interest in the concept of infrastructure in legal scholarship, including extensive analyses of the legal aspects of public infrastructure and socio-technical systems.Footnote ¹⁰ Of course, as a term, infrastructure is hardly new to legal discourse, given that it has an ordinary semantic meaning that denotes material constructions, facilities, and systems that support or enable some enterprise or basic societal function, reflecting the Latin derivation from infra—meaning “below”—and the French word structure. Footnote ¹¹ In legal scholarship, the term legal infrastructure is thus sometimes used to simply describe a collection of laws that supports social institutions—for instance, as “the socially available set of legal materials that economic actors can use to help govern relationships.”Footnote ¹² Yet, the term and idea of infrastructure as it now often appears across the social sciences and humanities is analytically much broader than this, and has come to describe a field of research in its own right, namely infrastructural studies.

Infrastructural studies is a broad church, a transdisciplinary field that is united by a general focus on the cultural aspects of social technologies, exhibiting research from fields as diverse as anthropology, science and technology studies (STS), history, geography, architecture, literary theory, and critical theory.Footnote ¹³ While there is no universal definition of what an infrastructure is within this broad research field, it is nevertheless possible to discern some core elements of infrastructures as both a physical thing and a way of thinking about things. A core theme has been to focus on the infrastructural qualities of things that operate below society as “system[s] of substrates.”Footnote ¹⁴ Thomas Hughes first brought our attention to the role of electricity infrastructures in large-scale social transformation, enabled through a mix of human creativity, expert management, and the engineering of nature.Footnote ¹⁵ Subsequent studies of the historical construction of technologies including air traffic control drew attention to infrastructures as socio-technical systems that work through norms, practices, and materials.Footnote ¹⁶ However, infrastructural studies really took off following Geoffrey C. Bowker and Susan Leigh Star’s influential work that conceives of infrastructures as interactional dependencies of social relations and agencies, opening up the window for expansive studies on more intangible infrastructures such as knowledge eco-systems.Footnote ¹⁷

It is not difficult to see how law can be encapsulated by such notions. Legal frameworks in many ways underlie not only physical but also more immaterial kinds of infrastructure, even if this is not always broadly appreciated. For instance, Mariana Valverde has foundationally shown how a wide array of legal tools—from zoning laws and materials regulations to contracts and financing deals—underpin every aspect of large-scale construction projects.Footnote ¹⁸ Geoff Gordon has elucidated on an international level how the standardization of Coordinated Universal Time (UTC) in 1884 enabled not only the coordination and interoperation of global travel and shipping routes, but also modern internet communication and global finance, where high frequency trading depends on microsecond time stamps.Footnote ¹⁹

Law in these contexts is often conceptualized as part of wider socio-material infrastructuresFootnote ²⁰ or as a relevant background variable for their governance, expansion and day-to-day operation.Footnote ²¹ Yet, it is also possible to think about law as a form of infrastructure in and of itself. Scholars within infrastructure studies sometimes draw parallels to law, suggesting that “infrastructures act like laws” in terms of “creat[ing] both opportunities and limits” for how knowledge practices take shape across time and space.Footnote ²² Thinking infrastructurally about law from such a perspective might lead scholars to examine the interoperation—or lack thereof—between different legal frameworks, how particular interpretations or normative constructs can “flow” across jurisdictional and regime boundaries, and the ways in which existing legal structures predispose new legal initiatives. Specifically regarding the ability to incorporate new legal initiatives, Léna Pellandini-Simányi and Zsuzsanna Vargha show in their study of financial law how lawmaking processes end up as “legal bricolage”, as legal amendments, like puzzle pieces, always have to fit the existing system of laws at multiple contact points.Footnote ²³ In other cases, legal regimes develop specifically to provide a kind of “normative scaffolding” for widely different regulatory areas—such as in the case of the EU Schengen acquis, which has come to encompass an expanding array of issues both in relation to EU law and relations with third countries.Footnote ²⁴ The contributions to this special issue explore both these perspectives to varying degrees. The analytical distinction between “law of infrastructure” and “law as infrastructure” is one we further develop in our conceptual framework article opening this issue.Footnote ²⁵

Another cross-cutting perspective running through the various contributions to this special issue is the way in which law and legal infrastructure relates to society, individual rights, exercises of power, and the distribution of social goods. In recent years, scholars within legal anthropology,Footnote ²⁶ TWAIL,Footnote ²⁷ and global administrative lawFootnote ²⁸ have drawn from infrastructural studies to critically examine the role of law in sustaining or accentuating, for example, structural injustices, discrimination, and rights violations. In his analysis of the “global mobility infrastructure,” Thomas Spijkerboer convincingly shows how the interaction of visa rules, aviation and security law, and national immigration codes produce highly discriminatory geopolitical zones for access to international travel.Footnote ²⁹ Spijkerboer’s contribution thus underlines the promise of follow-up studies using an infrastructural lens in this context, as such a lens further foregrounds the role of law to afford or restrict access to things, ideas, entities, and resources by creating flow or stoppage.Footnote ³⁰ On a broader level, a recent symposium in AJIL Unbound specifically explored how socio-material infrastructures, from colonialism to current-day state-building projects, continue to shape international law.Footnote ³¹ This emphasizes another key insight from infrastructure studies, namely how infrastructures constitute power, and the ordering that emerges from them.Footnote ³²

Vice versa, within the otherwise sprawling field of infrastructural studies, attention to legal structures and interactions, including across normative scales and specializations, is often left underexplored. At best, law is often considered as a background or passive variable. As the contributions to the above-mentioned AJIL Unbound symposium highlight, however, there is no denying that law, including international law, is often a dependent variable for other types of infrastructural projects, and the political, economic, and social relations underpinning them.Footnote ³³ Moreover, as the contributions to this special issue highlight, denying law’s power to shape the world risks underestimating the normative force of law and thereby misconstruing its role in society.Footnote ³⁴ Beyond an import of certain concepts and analytical modes of thinking for the benefit of legal theory, this special issue thus ultimately also aims to speak back and bring a more distinct focus on law and legal regulations to bear in infrastructure studies. To achieve this, the special issue develops a concept of legal infrastructures that can serve as both a theoretical and empirically generative research agenda, approaching what is taking place at the nexus between law, practices, and materials.

As the opening contribution, our conceptual framework invites a provocation to think of law as a form of infrastructure, developing a concept of legal infrastructures that draws not only from infrastructural studies, but also international legal theory and insights from the new materialist turn in legal scholarship. In our review of the infrastructural studies literature, we distil a conceptualization of infrastructures as entailing material, relational, and distributional elements. We articulate this conception of infrastructures with specific regard to foundational problems of legal thought across three analytical dimensions. We consider legal infrastructures, firstly, as socio-material formations that generate societal effects; secondly, as forms of social organization that recursively entangle to produce new configurations; and finally as inherently distributive and thereby affecting normative developments across traditional regime boundaries.

In her follow-up contribution, Jaya Ramji-Nogales turns to the analytically productive notions of infrastructural failures, dysfunction, and even breakdown, using the legal infrastructures related to the southwestern United States border as a focal point. In doing so, she unpacks a border infrastructure composed of overlapping regional, bilateral, national, and international rulesets, which creates far-reaching dysfunctions due to its partly opaque, discretionary, and incomplete nature. To develop this argument, she responds to our opening contribution by examining the material, relational, and distributive dimensions of this border legal infrastructure, using illustrations ranging from the contested legal basis of installing a floating barrier in the Rio Grande to infrastructural harms caused by the obligatory use of the CBP One smartphone app to make an appointment to apply for asylum. Ramji-Nogales’s contribution uses infrastructural dysfunction as a lens to highlight the role of political polarization in accelerating decay and even breakdown within legal infrastructures. As her analysis shows, such legal infrastructural failings include, among others, extra-legal constructions of physical infrastructures as well as an overstretched judicial system seeking to navigate a highly politicized environment, with at times contradictory results.

Pointing to a different kind of global bordering for human mobility, Frédéric Mégret draws attention to an omnipresent, but often overlooked or even taken-for-granted, legal object—namely non-immigration visas. His article highlights both the potential of infrastructural thinking to draw attention to so far under-researched constellations of legal rules and provisions, as well as legal infrastructure as an analytical lens for examining the distributional effects of law. In doing so, Mégret points to the “banality of arbitrariness” inherent in the day-to-day refusal of non-immigration visas,Footnote ³⁵ the granting of which remains a necessary precondition for regular international travel for large parts of the world’s populations. Deeply steeped in intersecting forms of exclusion, denials of—or even the impossibility of applying for—non-immigration visas bear considerable costs, impeding professional opportunities—including participation in academic conferences—the option of pursuing further education abroad, as well as vital family visits. Understanding infrastructure as consisting of law, administrative practices, their material manifestations, and situated conditions, Mégret’s empirically rich and nuanced analysis sheds light on the overlapping obstacles applicants face throughout the process of seeking to gain access to a non-immigration visa, frequently entrenching discriminatory patterns, especially regarding race and class.

Closely related, Christian Brown Prener and Thomas Gammeltoft-Hansen’s article examines citizenship as a focal point for their analysis of human mobility law as a multi-layered and densely interconnected legal infrastructure. As their contribution’s starting point, they use a legal infrastructural lens to understand human mobility law as a legal field that stretches across a plethora of interacting legal regimes, ranging from refugee and human rights law to aviation and labor law. To examine cross-regime interactions and co-constitutions typically overlooked by regime-specific analyses, they argue for instead using legal constructs that act as nodes connecting intersecting legal regimes as an analytical entry point. Brown Prener and Gammeltoft-Hansen demonstrate the analytical purchase of their approach by examining citizenship as such an “axial centrepiece” and “central organizing medium.”Footnote ³⁶ Ultimately, their analysis underlines the distributive effects of legal infrastructures, as citizenship enables, but importantly also prevents cross-border mobility for a sizeable proportion of the world’s populations, ultimately reproducing global socio-economic inequalities. At the same time, Brown Prener and Gammeltoft-Hansen’s contribution also directs our attention to how citizenship has changed over time due to the increasingly commonplace acceptance of dual citizenship. Such a change has provided opportunities for increased mobility to a small global elite, thereby again entrenching socio-economic inequalities, both globally and domestically.

Gavin Sullivan and Dimitri van den Meerssche turn to the relationship between law and digital infrastructures. Drawing on extensive interviews with policy officials and data engineers, their article provides a critical examination of Cerberus, the United Kingdom’s new digital bordering platform that is currently under development. As an “emergent algorithmic bordering infrastructure,”Footnote ³⁷ Cerberus combines forms of data that were previously held separately, ultimately with the aim of introducing algorithmic modes of “risk” detection. Their careful analysis demonstrates how this new digital infrastructure mediates and reconfigures EU data protection standards, such as a requirement for “reasonable suspicion.” More fundamentally, Sullivan and van den Meerssche show how legal standards become etched into this emergent digital infrastructure via a legal-technological translation process that in turn shapes how these legal norms are and can be understood. Such legal-technological processes of translation and reconfiguration have far-reaching consequences. Perhaps most importantly, Sullivan and van den Meerssche point towards what they call an “emergent dispositif of speculative suspicion,”Footnote ³⁸ flowing from the aim of pre-emptively identifying “risks” that are as-yet unknown. As they show, however, suspicion does not fall equally, as they problematize design features that, among other potentially detrimental implications, may ultimately exacerbate the risk of racial bias at the border. In sum, their article showcases the empirical and critical insights that can be gained by tracing how legal norms, as well as algorithmic and data practices are co-produced.

Legal infrastructures are also a particularly productive lens to understand processes of regionalization. Andrea Jiménez Laurence and Florian F. Hoffmann examine the malleability and ever-evolving character of the intersecting and entangled laws used and reshaped by cross-border movements in Latin America. Their analysis points to how legal infrastructures evolve over time as they are enacted in practice, and how thinking infrastructurally about law in this context can help question more conventional, static forms of legal analysis. Cross-border movements in Latin America are particularly illustrative in this context due to the way in which domestic legal instruments, regional rulesets, and international refugee and human rights law intersect—impacting not only human mobility, but also normative developments. To illustrate their argument, Jimenéz Laurence and Hoffmann use four vignettes to show how infrastructural entanglements can both hinder and facilitate cross-border mobility. Ultimately, their analysis underlines the considerable amount of agency those on the move have when navigating evolving, overlapping, and often incomplete entangled legal regimes, thereby shaping and reconstituting the normative entanglements themselves in the process.

Similar dynamics can be identified in relation to the Economic Community of West African States’ (ECOWAS) free movement regime. Here, Amalie Ravn Weinrich adds a focus on gendered obstacles to access. For the purposes of her article, she distinguishes between legal, physical, and technological dimensions of mobility infrastructures, analyzing gendered impediments to access across all three layers. Drawing on comprehensive interview material conducted with officials at the ECOWAS Commission, she traces the practices and perceptions of those ultimately responsible for managing and maintaining this legal infrastructure. As in the case of Latin America above, her analysis points to the problematization of intersecting legal frameworks, including domestic and regional laws, as well as their intimate ties to physical infrastructure, such as border crossing posts, and digital infrastructures, such as internet access. In conclusion, her article emphasizes the multi-layered, gendered obstacles to movement opportunities, reflecting enduring tensions between policy intentions, infrastructural design ambitions, and continuing challenges ultimately left within the domain of infrastructural “maintenance work.”

Drawing on a particular branch of new legal materialism, Thomas Gammeltoft-Hansen and Itamar Mann zoom in on the cruise ship as an object of international law and global capitalism in order to develop a novel take on understanding how both elements shape this particular type of international tourism. Seeking to develop a generalizable analytical framework for legal infrastructures, they offer three main concepts to understand the relationship between “international law and infrastructure” and “international law as infrastructure”Footnote ³⁹: Platform, object, and rupture.Footnote ⁴⁰ On the one hand, the concept of platform, understood as “large-scale webs of laws and materials,”Footnote ⁴¹ is used to interrogate the conditions based on which particular objects or practices are premised. Here, it is the rules of maritime commerce and transportation that have ultimately enabled the development of the cruise industry as a particularly predatory form of capitalism. On the other hand, a focus on the object serves as an explorative lens for charting this normative web, bringing widely different legal regimes into analytical relation. Simultaneously, a focus on the object serves as a corrective to the arguably in-built structural bias in infrastructure studies, and invites us to pay attention to physicality, legal, design and its concrete manifestations—here, onboard the cruise ship itself. Bringing the two together, the concept of rupture serves as a final analytical lens for understanding how relations between object and platform are constantly renegotiated and subject to change. In this case, Gammeltoft-Hansen and Mann point towards the COVID-19 pandemic and its major impact on the industry, with early outbreaks taking place onboard cruise vessels, lockdowns bringing the otherwise hypermobile industry to a near standstill, and ultimately exposing its frangible legal underpinnings. Taken together, they thus propose their three concepts as a roadmap for studying legal infrastructures even beyond the specific case of cruise ships.

Mariana Valverde concludes this special issue with a reflective contribution that looks back at an evolving literature on law and/as infrastructure through the lens of her own past research projects. In particular, she showcases the promise of empirical research on law and physical infrastructures. Her work on building contracts for large physical infrastructure projects, for example, has led her to question the promise of democratic accountability and transparency that making such contracts public may hold. Instead, she urges that empirical attention be turned to the fragmented and disordered local solutions and imaginaries that shape and breathe life into such large physical infrastructure projects. Such a focus equally enables moving beyond unhelpful analytical distinctions between the day-to-day operations of infrastructures. Echoing Ramji-Nogales’ intervention in this special issue on infrastructural breakdown in relation to the US border, Valverde encourages legal scholars to turn to infrastructure studies for conceptual inspiration to make use of the extensive scholarship unfolding on physical infrastructures, and their maintenance and decay across different disciplines, including with a focus on access and marginalization across the Global North and South. At the same time, she emphasizes the need for further attention on law and legal infrastructures within infrastructure and urban studies, ranging from building codes to legal rules on the circulation of materials and ultimately of legal documents themselves.

As the range of contributions to this special issue showcases, the concept of legal infrastructures covers a broad canvas. It can leverage insights from both infrastructural studies and legal theory. By doing so, it is intended to be realized as a conceptual and analytical framework of broad appeal, and is as such relatively agnostic about the methodological direction a researcher chooses to take when using or applying it. At the same time, however, it offers a conceptual toolbox that opens up particular avenues of analysis around themes such as infrastructural harm, maintenance, breakdown and failure, as well as distributive effects, ‘infrapolitics’Footnote ⁴², and unequal access to legal infrastructures—each of which resonate with wider debates in current international legal scholarship.