印度在美中兩大強權之間的第三方影響為何？本文利用事件資料庫探討兩個問題：（1）印度是否扮演牽動中美互動的關鍵角色？（2）若然，印度如何牽動中 美雙方互動？透過時間序列分析 1995 年至 2017 年間的美中印三邊互動行為紀 錄發現，在控制美中經濟相互依賴與兩國內部政權輪替的情形下，來自印度的 第三方影響確實存在於美中互動過程，也印證了印度以區域競爭者的身分，在 美中競逐中扮演牽制中國之角色。美印關係是影響中美決策者決定合作與衝突 的關鍵，印度的合作與否將影響美中交往的利弊分析與威脅認知。   

What role does India play as a third party in US-China interactions? This paper aims to answer the question based on event data with two steps. First, is India a significant third party when analyzing US-China relations? Second, if yes, how does India’s third-party effect work? By investigating the US-China-India triangular interaction from 1995 to 2017 with time-series analysis, I show that India’s third-party effect is significant in US-China relations and works as a regional competitor to check and balance China’s rise as the US strategy suggests. The analysis in this paper also indicates that US-India relations are the key for the United States and China to plan their next interactions. Furthermore, India’s cooperation is the crucial element to influence the perceptions of threat and the cost-benefit analysis of both the United States and China in their decision-making process.