Trilaterals and the Reorganisation of Northeast Asia’s Regional Order

In an era of intensifying competition over the international order in Northeast Asia, both major and non-major states have increasingly sought to use trilateral mechanisms distinct from bilateral and multilateral forms. In this context, this co-authored article discusses various types, origins, and influences of trilateral relations in international politics, as well as current and historical trilateral relations that have contributed to the emergence and transformation of regional orders. First, it categorises trilateral relations into four types: (1) three partners, (2) three rivals, (3) two partners against one rival, and (4) two rivals competing for one (potential) partner, encompassing cooperative and conflictual relationships among both three parties and three bilateral relations and clarifying each type’s characteristics and dynamics. Then, it offers a comprehensive way to understand the origins of trilateral relations, identifying three different, but complementary, sources for the formation of trilateral relations: structural balance of power, strategic interests, and a mix of structure and strategy. Lastly, it explores power dynamics both of and within trilateral relations, focusing on three dimensions of power: the trilateral’s collective power as a group, the power dynamics within trilateral relations, and the structural power exerted by the trilateral over its individual component states.