Deciding to Intervene: An Analysis of International and Domestic Influences on United States Interventions in Intrastate Disputes

Although the United States has been the most prolific intervener in the international system since the end of World War II, there has been little consensus among scholars regarding the motivations of U.S. interventions in domestic political disputes abroad. In addition, scholars do not agree on the relative effects of international factors and domestic factors on intervention decisions by the U.S. Previous research on the motivations of U.S. interventions has occurred within at least two distinctive “streams” of literature: (1) studies of state interventions; and (2) studies of the use of military force by the U.S. Hypotheses regarding U.S. interventions in intrastate disputes are derived from the previous literature, and the hypotheses are tested using recently-compiled data on intrastate disputes and U.S. interventions in intrastate disputes occurring between 1945 and 2002. The results suggest a combination of international factors, including geographic proximity and ideological linkage, significantly influence the decisions of the U.S. to intervene in intrastate disputes. The results also suggest international factors are generally more important than domestic factors, and the effects of both domestic factors and international factors on U.S. intervention decisions may differ depending on the specific type of intervention and the time period.

自第二次世界大战结束以来，美国始终是国际体系中干预行动最为频繁的国家，但学界对于美国介入海外国内政治争端的动机始终未达成共识。此外，学界对于国际因素与国内因素在美国干预决策中的相对影响也存在分歧。过往针对美国干预动机的研究，至少可划分为两类独特的学术研究脉络：其一为国家对外干预研究，其二为美国军事力量运用研究。本研究针对美国介入国内冲突的相关假设均源自既有学术文献，并采用1945年至2002年间的国内冲突与美国介入国内冲突的最新汇编数据集，对上述假设进行检验。研究结果显示，包括地理邻近性与意识形态关联在内的多项国际因素，会对美国介入国内冲突的决策产生显著影响。研究结果同时表明，国际因素总体上较国内因素更为关键，且两类因素对美国干预决策的影响，会因干预的具体类型与所处时段不同而存在差异。