Regionalism has long been recognised as an important mechanism through which different actors organise cooperation, manage interdependence and respond collectively to shared challenges. From early studies of regional integration to more recent scholarship on comparative and global regionalism, the field has progressively moved beyond formal integration projects to encompass the diverse political processes, institutions and governance arrangements through which regions are socially and politically constructed (e.g. Hurrell, 1995;Fawcett, 2004;Acharya, 2007;De Lombaerde et al., 2010;Börzel and Risse, 2016;Söderbaum, 2016;Lenz and Söderbaum, 2025;Acharya et al., 2026). Regional organisations remain central institutional expressions of regionalism, but increasingly coexist with more flexible governance arrangements and interregional partnerships.Today, however, regionalism is developing under markedly different international conditions. Rather than confronting isolated policy challenges, regional actors increasingly operate in an environment characterised by interacting geopolitical, economic, environmental and societal crises. Polycrisis, highlights not simply the simultaneity of multiple crises, but their interaction across sectors and governance levels, whereby pressures in one domain can intensify vulnerabilities in others and generate cascading effects that exceed the sum of their individual parts (e.g. Tooze, 2022;Lawrence et al., 2024;Brosig, 2025;Rakowski et al., 2025). These interactions can transmit pressures between domestic, regional and global levels, shaping both the demands placed on regional cooperation and the capacity of regional actors to respond. Accordingly, the regional level is not simply another scale of analysis, but a strategic arena where the effects of interconnected crises are mediated, contested and governed.Against this backdrop, this Research Topic examines how regionalism is evolving under conditions of polycrisis. Rather than simply considering whether regionalism is strengthening or weakening, the contributions explore how regional governance arrangements and interregional partnerships are adapting to an increasingly interconnected landscape of crises. Together, they suggest that polycrisis is less an explanation for the trajectory of regionalism than a critical context that reveals and, in some cases, accelerates the adaptive capacities, institutional diversity and multilevel character of contemporary regionalism.
As a whole, the contributions point to three broader, analytically distinct insights: how regional institutions adapt to crisis pressures; how different forms of cooperation coexist and combine; and how regional governance extends across governance levels and external relationships.First, the collection shows that regionalism under conditions of polycrisis is characterised by institutional adaptation, rather than uniform trajectories of integration or decline. Read together, the Latin American contributions by Detlef Nolte, Karina Pasquariello Mariano and María Victoria Alvarez illuminate complementary dimensions of this transformation. Whereas the first two revisit the concept of Liquid Regionalism to explain how institutional flexibility, contestation and resilience coexist, the latter demonstrates the practical governance challenges that arise when regional organisations confront interconnected political, humanitarian, migration and public health crises. Collectively, these articles suggest that institutional fluidity should not automatically be interpreted as either weakness or resilience: adaptation may sustain continuity and responsiveness, but it may also coexist with weaker coordination, fragmentation or institutional erosion.Second, the articles demonstrate that regionalism increasingly develops through differentiated forms of cooperation. That is, through the coexistence and combination of different institutional modes. Contemporary regional cooperation rarely relies on a single model. Instead, it combines formal organisations with bilateral initiatives, issue-specific arrangements and other flexible forms of cooperation. This pattern is illustrated by Yelena Izteleuova's analysis of Central Asia, which shows how bilateral and multilateral cooperation function as complementary (although sometimes competing) components of regional governance. Likewise, Anna Ayuso's examination of European Union-Latin America relations illustrates how the EU has recalibrated its external instruments in response to geopolitical competition, the emergence of the Global South and an increasingly multipolar international order. Read jointly, these studies suggest that regionalism is becoming more institutionally differentiated, rather than institutionally uniform. Such flexibility may facilitate immediate responses, but may also weaken and fragment regional multilateral cooperation.Third, the collection demonstrates that contemporary regionalism increasingly extends across governance levels and external relationships. The focus here is, therefore, not primarily on the coexistence of institutional forms, but on interactions linking regions with external powers, global institutions and interregional partnerships. Read together, the contributions by Maria J. Garcia and Gomez Arana, Johannes Muntschick and Tiffany Williams illustrate this evolution from complementary perspectives. Garcia and Gomez Arana show how Trade and Sustainable Development chapters have become important mechanisms for promoting sustainability through interregional cooperation, while simultaneously reflecting persistent asymmetries in regulatory influence and economic power. Muntschick demonstrates how cooperation on green hydrogen between the European Union and Southern Africa has become increasingly shaped by competing security, development and sustainability narratives following Russia's invasion of Ukraine. Williams, in turn, broadens the conceptual discussion by proposing metamodernism as a lens for understanding metacrisis and geopolitical transformation in the Euro-Atlantic area, highlighting the uncertainty, contradiction and institutional oscillation that increasingly characterise contemporary international politics.
Collectively, the articles highlight the value of bringing comparative regionalism into closer dialogue with emerging scholarship on polycrisis. While polycrisis research has primarily examined global systemic dynamics, and comparative regionalism has traditionally focused on variation in regional institutions and integration processes, the contributions show the analytical value of examining how regionalism evolves under sustained systemic disruption. The regional level emerges as a critical arena where interconnected crises materialise, governance challenges become intertwined, and collective responses are negotiated.More fundamentally, the collection encourages a more dynamic understanding of regionalism. Rather than viewing regionalism through linear assumptions of either progressive integration or institutional decline, the contributions emphasise how regional cooperation increasingly develops through adaptive forms of regional governance. Across different regional contexts, the articles consistently point to three interconnected dynamics: institutional adaptation, differentiated forms of cooperation, and multilevel governance spanning regional, interregional and global scales. Together, these insights move beyond binary assessments of regionalism as either resilient or fragile, successful or failing, and instead portray it as an evolving process through which states and regional actors continuously adjust institutions, governance arrangements and patterns of cooperation in response to an increasingly complex international environment.Overall, these contributions underline the continuing relevance of comparative regionalism for understanding how regions respond to sustained systemic disruption and point towards future research on regional cooperation. They also open space for multi-and interdisciplinary research, including political economy, sociology and law, on how polycrisis intersects with regionalism studies. We are grateful to all authors and reviewers whose engagement made this Research Topic possible and whose contributions help advance the study of regionalism in a turbulent international order.
