On 5th April, ETH Zurich published a Brief which is the first of 3 on the ways the international community has responded to the new developments to preserve and strengthen the norm against CW use. It first offers a short historical overview of chemical warfare, followed by a review of resurgent use of toxic agents. It next introduces the CWC. A discussion of the challenges the new-found utility of such agents pose to the convention then follows. Reassuringly, it says that while terrorists are known to have had a long-standing interest in poisonous substances, incidents have remained far and few between; but it does mention large-scale opportunistic use of an industrial toxicant in combat.