军政竞争、灵活追随与泰美安全合作弱化OACHSSCD

An alliance is essentially a security cooperation relationship concluded between two or more countries.Within the U.S.-led hub-and-spokes alliance system in the Asia-Pacific established after World War Ⅱ,US security cooperation with Japan,South Korea,and Australia has remained consistently robust,while U.S.ties with New Zealand and the Philippines have experienced a process from decline to enhancement.In contrast,why has Thailand-U.S.security cooperation exhibited a trajectory of weakening?Existing scholarship tends to explain this phenomenon predominantly from a great-power perspective or focuses on discrete historical periods.This article offers an alternative theoretical framework by examining the evolution of Thailand-U.S.security cooperation from the standpoint of the weaker ally.The study identifies two primary factors shaping Thailand's posture toward security cooperation with the United States.First,the interests of Thailand's decision-making elites:amid persistent civil-military competition,the paramount objective of Thai elites is the consolidation and perpetuation of political power.Second,the costs of alignment with the United States:under a strategy of flexible band-wagoning,the principal metric by which Thailand assesses the costs of taking sides is the perceived power gap between China and the United States.Driven by the interplay between elite interests and alignment costs,Thailand-U.S.security cooperation has weakened across three distinct phases:Comprehensive Strategic Cooperation(1954-1974),Limited Strategic Cooperation(1975-2008),and Nominal Strategic Cooperation(2009—present).This framework contributes to understanding weak-state agency in the evolution of asymmetric alliance security cooperation and offers policy-relevant implications for assessing the trajectory of U.S.security relations with Thailand and other Asia-Pacific treaty allies.