We combine insights from strategic alliance literature, international business and economic geography to explore where firms form international alliances. We focus specifically on the importance of micro-locational factors such as global cities. This paper is an attempt to provide a better understanding of the complex, multilevel factors that interact to make a particular partner in a particular location more likely to be chosen by a focal firm. We take an explorative methodological approach trough a cluster analysis of international alliances made by American companies in 2015. One main contribution is the effect of micro-locational characteristics when studying international alliance formation at a city level.