With the July 2017 Sydney hydrogen sulfide plot, there is some evidence that the Islamic State has transferred its chemical warfare (CW) expertise from the battlefield to its foreign terrorism activities. Despite this development, Islamic State appears to put scant organizational stock into the use of CW to advance its strategic goals. Though this lack of enthusiasm cannot be confirmed without secret intelligence or broad primary source data, the Islamic State’s most obvious means of threatening CW attacks—its affiliated propaganda organs—appear to lack any mention of CW events, prowess, or alleged planning. Ultimately, the Islamic State CW experiment seems to predict little about the future of the group’s chemical terrorism.
Binder, Markus K., Jillian M. Quigley, and Herbert F. Tinsley. 2018. "Islamic State Chemical Weapons: A Case Contained by its Context?" CTC Sentinel 11 (March): 27-31. https://ctc.usma.edu/islamic-state-chemical-weapons-case-contained-context/