▪ Abstract This article reviews three recent developments in international cooperation theory: the introduction of nonstate actors, the study of norms and ideas, and increased examination of the effectiveness, or impact, of international cooperation. Through the lens of the agent-structure debate, we critique the literature that addresses these themes. We argue, first, for a view of structure that goes beyond material properties; second, that more attention could be paid to what distinguishes agency in actors; and third, that this would provide insights into how reflexivity and learning, as well as preference and identity formation, contribute to structural transformation in the international system through iterated processes of cooperation. We also develop ways of applying the agent-structure debate to empirical as well as metatheoretical questions. The article concludes by discussing directions for further research.

There is growing recognition that using the properties of nature through nature-based solutions (NBS) can help to provide viable and cost-effective solutions to a wide range of societal challenges, including disaster risk reduction (DRR). However, NBS realization depends critically on the governance framework that enables the NBS policy process. Drawing from three case studies in Nocera Inferiore (Italy), Munich (Germany), and Wolong (China), we identify key governance enablers—the contextual preconditions, policy processes, and institutions—that proved essential for NBS initiation, planning, design, and implementation. In the three cases, interviews confirm the success of the NBS measures and their benefits in terms not only of DRR but of multiple ecological and social–economic co-benefits. Results highlight critical governance enablers of NBS, including: polycentric governance (novel arrangements in the public administration that involved multiple institutional scales and/or sectors); co-design (innovative stakeholder participatory processes that influenced the final NBS); pro-NBS interest and coalition groups (organized pressure groups that advocated for an NBS); and financial incentives (financing community-based implementation and monitoring of NBS). Findings show that the transition to NBS can contribute to multiple global agendas, including DRR, climate change adaptation, and sustainable development.

Global environmental governance is growing increasingly complex and recent scholarship and practice raise a number of questions about the continued feasibility of negotiating and implementing an ever-larger set of global environmental agreements. In the search for alternative conceptual models and normative orders, regional environmental governance (REG) is (re)emerging as a significant phenomenon in theory and practice. Although environmental cooperation has historically been more prevalent at the regional than at the global level, and has informed much of what we know today about international environmental cooperation, REG has been a neglected topic in the scholarly literature on international relations and international environmental politics. This introduction to the special issue situates theoretical arguments linked to REG in the broader literature, including the nature of regions, the location of regions in multilevel governance, and the normative arguments advanced for and against regional orders. It provides an overview of empirical work; offers quantitative evidence of REG's global distribution; advances a typology of REG for future research; and introduces the collection of research articles and commentaries through the lens of three themes: form and function, multilevel governance, and participation.

This paper examines how local communities adapt to climate change and how governance structures can foster or undermine adaptive capacity. Climate change policies, in general, and disaster risk management in mountain regions, in particular, are characterised by their multi-level and multi-sectoral nature during formulation and implementation. The involvement of numerous state and non-state actors at local to national levels produces a variety of networks of interaction and communication. The paper argues that the structure of these relational patterns is critical for understanding adaptive capacity. It thus proposes an expanded concept of adaptive capacity that incorporates (horizontal and vertical) actor integration and communication flow between these actors. The paper further advocates the use of formal social network analysis to assess these relational patterns. Preliminary results from research on adaptation to climate change in a Swiss mountain region vulnerable to floods and other natural hazards illustrate the conceptual and empirical significance of the main arguments.