To the Editors (Tongª Kim writes): In “To Arm or to Ally?” Keren Yarhi-Milo, Alexander Lanoszka, and Zack Cooper pre- sent an elegant and powerful theory that explains conditions under which a great power (in their case, the United States) offers a client state arms, an alliance commit- ment, or both. 1 Their article does not give due attention, however, to what motivates a patron to provide security assistance to clients in the ªrst place—especially its de- sire to inºuence its clients to obtain concessions in military, political, economic, and other policies. 2 Below I explain how Yarhi-Milo, Lanoszka, and Cooper’s conceptual- ization of key variables inadvertently plays down the role of inºuence-seeking in U.S. policy. First, Yarhi-Milo, Lanoszka, and Cooper’s conceptualization of arms transfers does not reºect the wide range of ways in which a patron can support a client and the signiªcant differences among the types of arms transfers with regard to buying inºu- ence. Their conceptualization of arms transfers, in which “a state gives another state weapons to augment its military capabilities” (p. 95), “covers multiple methods of pro- vision, including sales, grants, and loans” (p. 97). As they discuss at the beginning of the article, however, the United States spends large sums of money on security assis- tance worldwide, a signiªcant portion of which is spent on things other than U.S. arms (p. 91). Israel, for example, has been allowed by the U.S. government to use about Tongª Kim is Assistant Professor in the Department of International Affairs at Vesalius College. For helpful comments, he is grateful to Carolin Liss and Luis Simón. Keren Yarhi-Milo is an assistant professor of politics and international affairs in Princeton University’s Pol- itics Department and the Woodrow Wilson School for Public and International Affairs. Alexander Lanoszka is Lecturer in the Department of International Politics at City, University of London. Zack Cooper is a se- nior fellow at the Center for Strategic and International Studies. 1. Keren Yarhi-Milo, Alexander Lanoszka, and Zack Cooper, “To Arm or to Ally? The Patron’s Dilemma and the Strategic Logic of Arms Transfers and Alliances,” International Security, Vol. 41, No. 2 (Fall 2016), pp. 90–139, doi:10.1162/ISEC_a_00250. Subsequent references to this article ap- pear parenthetically in the text. 2. For a supply-side analysis of security provision through alliances and an argument that empha- sizes the importance of nonmilitary concessions in alliance politics, see Tongª Kim, The Supply Side of Security: A Market Theory of Military Alliances (Redwood City, Calif.: Stanford University Press, 2016). International Security, Vol. 42, No. 3 (Winter 2017/18), pp. 183–186, doi:10.1162/ISEC_c_00307 © 2018 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology. Correspondence: Patron-Client Relationships Correspondence Tongª Kim Keren Yarhi-Milo, Alexander Lanoszka, and Zack Cooper Arms, Alliances, and Patron-Client Relationships 183