ISIS Foreign Fighters and the Threat of CW Use

By: Zamawang Almemar, Chemical and Biological Defense Analyst

There has been a major growing concern by the U.S. and the international community regarding ISIS foreign fighter returnees and their interest in using Chemical Weapon (CW) devices on Western targets. After numerous reports and incidents of chemical attacks by ISIS and their use of various chemical weapons, such as mustard and chlorine gas in Iraq and Syria from 2014 to 2017, authorities initiated major campaigns to counter ISIS CW attacks.


Recently, authorities have been fearing the threat of ISIS foreign fighters returning to their home countries and using their battlefield skills to manufacture and deploy chemical weapons on Western targets. In these potential attacks against the general population the First Responders will become the first line of defense in such attacks. Therefore, it is crucial for them to be fully informed about this threat so that they can continuously provide the public with invaluable information and education regarding protection measures, as responding to such a crisis that would undoubtedly cause mass chaos. The CW of choice for these lone wolf attackers would most likely be either sulfur mustard or the common Toxic Industrial Chemical (TIC) - chlorine. Therefore, it is crucial for first responders to be able to distinguish between these two chemicals and know how to respond to each incident respectively.


Sulfur mustard, commonly known as mustard gas, is a light to dark brown oily liquid that causes significant respiratory problems if inhaled. It also causes skin irritation and blindness in individuals exposed to these chemicals. Skin blisters are also another major side effect of mustard gas, but more importantly, the agent can be fatal when used in high concentrations. Since it is heavier than air, it stays close to the ground. Mustard gas was first introduced as a chemical warfare agent by the Germans during World War I and the agent was also used by the Saddam Hussein regime in 1988 on the Kurdish town of Halabja, which resulted in 5,000 deaths. More recently, it has been reported that ISIS manufactured and used a crude mixture of mustard gas against the general population and ground forces in several towns in Iraq and Syria.

Secondly, chlorine gas is a toxic gas that causes irritation in the respiratory system. It is a yellow-green gas with an odor of household bleach. Respiration becomes extremely difficult, accompanied by irritation of the eyes. Additionally, the most prominent effect of chlorine inhalation is burning pain in the throat and the eyes, followed by excruciating pain and suffocation. The victim will become weak and unconscious from continuous exposure to chlorine gas. ISIS is known to have used chlorine gas against the ground forces in Iraq and Syria numerous times.se.


Authorities and experts in the field are now concerned about ISIS continuing to use their recruitment strategies to rally supporters and sympathizers online to pledge their allegiance to the terrorist group and agree to conduct a CW attack on a Western target. It is possible that these ISIS lone-wolf sympathizers are busy experimenting and testing the next unconventional weapon in their basements.


While the U.S.-led campaign almost entirely eradicated the Islamic State’s physical caliphate in Iraq and Syria, there has however been increased concern by Western authorities about surviving foreign fighters evading their home countries’ security systems, accompanied by their desire to make a noticeable comeback that may potentially include resorting to using unconventional weapons in their homeland. This will continue to be a priority of subject matter experts (SMEs) in the field who are concerned with the livelihoods of the general population and the freedom they enjoy. Thus, educating our First Responders about this imminent threat will most likely be our first line of defense.