Widespread fear that hosting refugees will mean more terrorism in host states is at the heart of the `refugee crisis'. Yet, we lack rigorous evidence for such claims. This article theoretically unpacks how and under what conditions transnational refugee movements plausibly lead to different types of terrorist outcomes. Combining original data with a multi-pronged approach involving a treatment-placebo design as well as instrumental variable estimation, we provide systematic and robust evidence that sheds new light on the security implications of forced migration. Our findings challenge the claim that hosting refugees heightens the risk of ``importing'' terrorist attacks against nationals of host countries, especially in developed countries. However, in these countries refugees themselves are particularly prone to becoming the targets of terrorist attacks by natives, driven by fear and revenge. Dominant policy responses to the refugee crisis that raise fears and suspicions are therefore not only ill-suited, but potentially counterproductive.