Chemical terrorist attacks by non-state actors have traditionally been characterised as low probability events; however, the apparent normalisation of chemical weapons use, including by terrorists, in the ongoing conflict in Syria is causing some in the international security community to question whether it will remain low probability. For Europe there is an additional potential concern, namely the numbers of EU citizens who are “foreign fighters” and whose return from the conflict zone might also result in “importing” chemical weapons use. This article examines the rise of the “chemical weapons-returning foreign fighter” narrative and considers aspects of the European response. These responses predate the current concerns and include important efforts to create a robust public health response, such as early alert and communication systems, so that the attractiveness of these weapons being used within a European context might be reduced. Although there are limitations as to how far one can transfer what happens in a Syrian context to Europe, the suggestion is made that some of the framing assumptions within this response architecture may be now inadvertently limiting the potential to identify and respond to chemical attacks.