This article studies variation in conﬂict theater choice by Western jihadists in an effort to understand their motivations. Some militants attack at home, whereas others join insurgencies abroad, but few scholars have asked why they make these different choices. Using open-source data, I estimate recruit supply for each theater, foreign ﬁghter return rates, and returnee impact on domestic terrorist activity. The tentative data indicate that jihadists prefer foreign ﬁghting, but a minority attacks at home after being radicalized, most often through foreign ﬁghting or contact with a veteran.
Many well-established explanations for war suggest that cyber weapons have a greater chance of being used offensively than other kinds of military technologies. This response article introduces a research agenda for the study of cyber war, and offers an example – principal-agent problems in cyber operations – to demonstrate how rigorous theoretical and empirical work may proceed.