What drives foreign state support for rebel organizations? While scholars have examined the geopolitical and organizational factors that fuel foreign support, the role of rebel leaders in this process remains understudied. In this article, we propose that rebel leaders personal backgrounds shape their ability to obtain foreign support during conflict. In particular, we argue that rebel leaders with significant prior international experiencesincluding study abroad, work abroad, military training abroad, and exileare at an advantage in securing wartime external support for their organizations. These experiences provide opportunities for would-be rebel leaders to interact with a multitude of foreign individuals who may later enter politics or otherwise gain prominence in their respective societies, allowing them to build interpersonal social networks across borders. Such networks offer key points of contact when rebel leaders later seek foreign backing. We test this theory using data from the new Rebel Organization Leaders (ROLE) database, finding robust support for our argument as well as the broader role of rebel leader attributes in explaining external support. Our results underscore the value of incorporating individual leaders and their social networks more squarely into the study of modern war.