Introduction

This introductory chapter sets the context for the edited volume, which seeks to understand and explain the increased presence of minilateral arrangements in the Indo-Pacific since the late 2000s. The focus is particularly on the Quadrilateral Security Dialogue and the Lancang-Mekong Cooperation mechanism. We argue that the emergence of these minilaterals has been fuelled chiefly by two factors, specifically the rising doubts over the sustainability of the US leadership and its alliance network in the region, as well as the inadequacies of the multilateral arrangements centred on the Association of Southeast Asian Nations (ASEAN) in resolving strategic regional challenges. Dominated by non-ASEAN powers, these minilateral mechanisms—defined as groupings that comprise between three and nine countries, and are relatively exclusive, informal and functional—could hold important consequences for the evolution of the regional security architecture. In addition to discussing increasing minilateralism in the Indo-Pacific, the chapter also examines how the concept of minilateralism has been treated in the extant literature, and offers an overview of the edited volume.