Military alliances are an important feature of major power competition. One way for a major power to increase its relative power is to drive a wedge in a rival’s alliance. Why and when does a major power do so? I propose a theory of strategic opportunity, which holds that a major power seeks to drive a wedge in the rival’s alliance by offering economic aid to a rival’s protégé when that country experiences a rapid deterioration in its relations with its patron. I test my theory on major power rivalry dyads and find empirical support for my argument on a set of directed dyad-year observations between 1960 and 2010. The findings contribute to our understanding of alliance politics and strategic considerations behind using economic carrots in major power rivalry.
Hankyeul Yang (Sat,) studied this question.