As Syria’s southern neighbour, the Hashemite Kingdom of Jordan has been deeply affected by every twist and turn of the Syrian war. Jordanian officials claim that anywhere from 650,000 to 1,300,000 Syrian refugees have fled to Jordan since 2011, impacting the kingdom’s alreadyprecarious economy. But Jordanian officials are also worried about the security of their own borders, and especially of IS terrorism threatening Jordan both from without and from within. Jordanian security policy toward the Syrian war has shifted over the years, from an initial focus on the Assad regime to an absolute fixation on the dangers of IS. This article examines the shifts in Jordanian security priorities and in the kingdom’s responses to both wars: the war between Assad and the Syrian rebels, and the war between IS and the anti-IS coalition. With two wars across its northern border, Jordanian officials have considered multiple possible scenarios and outcomes of these conflicts, all of which seem negative for Jordan, varying only by degree.

Curtis R. Ryan is Professor of Political Science at Appalachian State University in North Carolina, USA. He is the author of many articles and chapters on Jordanian domestic politics and foreign policy, and has written two books: Jordan in Transition: From Hussein to Abdullah (Lynne Rienner, 2002) and Inter-Arab Alliances: Regime Security and Jordanian Foreign Policy (University Press of Florida, 2009). His latest book, Jordan and the Arab Uprisings, is forthcoming in 2018.