In recent decades, the development of trilateral institutions has proliferated widely in East Asia. Inspired by an analysis of minilateralism, prevailing studies have spoken highly of trilateralism, as trilateral groupings offer greater outputs for regional community building. In contrast to the prevailing optimism, this study argues that trilateralism – the miniature form of multilateralism – is not unconditionally “good.” A three‐party arrangement is seen as potentially problematic, and its effectiveness is not guaranteed. This research examines two potential structural uncertainties for trilateralism in East Asia, which are the efficiency problem and the solidarity problem. This article sets up a theoretical model for examining the utility and operability of trilateralism in East Asia, and presents a cost–benefit analysis by comparing the utility of trilateralism with those of bilateralism and multilateralism. In East Asia, countries have been struggling with bilateral conflicts, and the prevailing logic of rivalry has led to the pursuits of “relative gains.” Thus, three preconditions are required in order to establish a “good” trilateralism: firm shared interests that prevent trilateral agreements to be eclipsed by embedded bilateral approaches, stable bilateral ties that ensure the operability of trilateral arrangements, and an effective leading country for implementing coherent policy responses. This article also enacts theories into practices and explains the performances of three trilateral relations (US–Japan–Australia, US–Japan–Korea, and China–Japan–Korea) in East Asia.

中文翻译：

---

什么使好三方主义？东亚三边主义实用化理论

近几十年来，三边机构的发展在东亚广泛扩散。受到对小边主义分析的启发，当前的研究高度评价了三边主义，因为三边集团为区域社区建设提供了更大的产出。与普遍的乐观主义相反，这项研究认为三边主义（即多边主义的缩影）并不是无条件的“良好”。三方安排被认为可能存在问题，并且不能保证其有效性。这项研究考察了东亚三边主义的两个潜在结构不确定性，即效率问题和团结问题。本文建立了一个理论模型来检验三边主义在东亚的效用和可操作性，并通过比较三边主义与双边主义和多边主义的效用来进行成本效益分析。在东亚，各国一直在为双边冲突而苦苦挣扎，普遍的竞争逻辑导致人们追求“相对利益”。因此，建立“良好的”三边主义需要三个先决条件：牢固的共同利益，以防止三方协议被嵌入的双边方法所掩盖；稳定的双边关系，确保三边安排的可操作性；以及一个有效的领导国，以执行连贯一致政策回应。本文还将实践中的理论付诸实践，并解释了三个三边关系（美日澳大利亚，美日韩大韩民国和中日韩大韩民国）的表现。