The Washington Post has reported that ISIS used an improvised chemical weapon containing chlorine to attack an Iraqi police patrol in Balad, north of Baghdad, in September, injuring 11 officers. Chlorine is readily available in Iraq given its widespread use for water treatment.
The good news is that ISIS’s use of chlorine indicates that it has not gained access to more toxic agents located at Muthanna, Iraq’s former chemical weapon production complex, which the group seized in June. That complex contains two bunkers with abandoned and degraded chemical agents and munitions that were sealed shut with concrete by UNSCOM almost twenty years ago. Breaching the bunkers to obtain the material inside would be extremely hazardous and would not likely yield readily usable agent or munitions given their age and storage conditions.
The bad news is that this attack is probably only the beginning. ISIS is the latest incarnation of the group Al-Qaeda in Iraq (AQI) which has had a long-standing interest in chemical weapons. AQI conducted a string of attacks in 2006 and 2007 that combined chlorine gas tanks and improvised explosive devices (IEDs). Due to the poor design of these improvised chemical weapons, most of the casualties were caused by the explosive component of the bomb, not the chlorine. AQI stopped using chlorine-laced IEDs due to their perceived ineffectiveness and a concerted effort by US intelligence and military forces to break up the network that had been constructing the weapons. ISIS, like AQI, has demonstrated a willingness to engage in extreme levels of violence, such as beheading captured fighters and civilians and conducting mass casualty attacks. The use of chlorine or other chemicals by ISIS fits this pattern of escalating violence and violation of norms to maximize the shock value of their actions.
Given the large swath of Syrian and Iraqi territory that ISIS now controls, the inability of local forces to launch offensive operations against ISIS, and the unwillingness of the Obama Administration to deploy even small numbers of U.S. soldiers in a combat role in Iraq, ISIS will likely be able to continue carrying out such attacks if they desire. Hopefully they will not learn any lessons from AQI’s previous experiments with this form of chemical terrorism.