Should We Fear the Unconventional? Why ISIL’s Chemical Weapons Are Causing the West to Panic

By Farnaz Alimehri, Columnist of the Georgetown Security Studies Review

On February 12, 2016, CIA Director John Brennan confirmed that the Islamic State of Iraq and the Levant (ISIL) used chemical weapons – specifically mustard and chlorine gas – and may use them again, as it has the capacity to produce more.[1] US official speculation about ISIL’s chemical weapons use dates back to December 2012, and this week the Organization for the Prohibition of Chemical Weapons (OPCW) likewise confirmed that mustard gas has been used in Iraq and that sarin gas has been used in Syria .[2]

ISIL’s chemical weapons use raises serious concerns about non-state actors’ access to weapons of mass destruction (WMD) and reinforces fears of a possible terrorist attack with chemical, biological, radiological, and/or nuclear (CBRN) weapons in the West. The European Union (EU) member states have begun individually training their forces on how to respond to a CBRN attack, and the United States has also been reconsidering various options to mitigate the impact of an unconventional attack on US soil.[3]

These preparations beg the question: what makes a CBRN attack more concerning than a conventional one? While conventional weapons have historically inflicted many more casualties than unconventional weapons, ISIL’s acquisition and use of chemical weapons nonetheless requires a deeper look at WMD. Certain elements of unconventional weapons distinguish them from regular weapons, making them particularly worrisome to the West. Four factors stand out:

First, current international law is ineffective at denying unconventional weapons to non-state actors. International treaties like the Biological Weapons Convention, the Nonproliferation Treaty, and the Chemical Weapons Convention have drawn a red line between acceptable and unacceptable behavior in warfare, with various different mechanisms designed to intrusively verify state compliance (more so than other kinds of international treaties). Although these measures can help prevent WMD or CBRN materials from falling into non-state actors’ hands, they are not particularly useful when a non-state actor already has access to old CBRN weapon reserves, or can produce these weapons themselves. Non-state actors are not covered by treaty obligations and thus, ISIL remains relatively unencumbered by international law in their acquisition of CBRN materials.

Second, an international taboo has been associated with the use of WMD, based in customary international law.[4] The taboo against nuclear weapons use, in particular, is supported by the International Court of Justice ruling in 1996, which found the use or threat of nuclear weapons contrary to the rules of international and humanitarian law. ISIL is thus challenging the international norm against the use of WMD, forcing many in the West to reevaluate this approach to arms control.

Third, because of the WMD taboo, the psychological impact of a terrorist attack with unconventional weapons is magnified. The impact and effects of a CBRN attack are wide- ranging and disparate. For example, a blistering chemical agent will affect the human body very differently than a nerve chemical agent, and this uncertainty can inspire terror. Many find the idea of suffocating by poison gas or being exposed to a disease much more terrifying than meeting their end at the barrel of a gun. The impacts are so great that in 1995, after the sarin gas attack in Tokyo, four out of five people believed they had been affected by the attack. Tests later revealed they were only suffering from anxiety.[5]

Fourth, unconventional weapons are further distinct from conventional weapons due to their secondary and tertiary effects. An unconventional attack can produce casualties both in the short and long term. Contamination may persist in water systems or agriculture, and effects can be passed on genetically to future populations. The Iran-Iraq war, for example, revealed the risks of what is referred to as “low-dose exposure.”[6] In spite of limited access to testing, Iranian scientists have suggested that citizens outside the initial blast areas were dying of low-dose exposure to mustard gas, causing the number of estimated casualties to rise from 50,000 in 1991 to 70,000 in 2002. They also suggest that the latency for some of the effects of chemical weapons can be a period of about 40 years, with the numbers of those affected continuing to rise today.[7] There is not enough evidence to confirm that other factors were not involved in this case, but it reveals a daunting grey-area in our knowledge and research of the effects of WMD.

When taken together, the West’s military training responses reflect the new and unique threat that a CBRN terrorist threat poses. The international community’s next move ought to focus on preventing such an attack from taking place. The best opportunity to find and eliminate ISIL’s access to chemical weapons is destroying old weapons in Libya, Syria and Iraq, or transporting them out of the country. Controlling export controls of CBRN materials – i.e. radiological sources or chemical precursors – is similarly essential. Finally, Syrian and Iraqi scientists with knowledge to create these weapons must be given opportunities elsewhere in order to mitigate the risk of them selling their knowledge to ISIL. These measures require working with international allies to not only ensure verification of their materials, but also to bolster international monitoring and export controls. Successful arms control against a potential terrorist threat requires a truly multilateral effort.

[1] Jack Moore, “CIA Director: Isis Has Used and Can Continue to Make Chemical Weapons,” Newsweek, February 12, 2016, accessed February 16, 2016,

[2] JP Zanders, “Chlorine: A Weapon of Last Resort for ISIL? (Part 2)” The Trench, February 18, 2015, accessed February 17, 2016,

[3] Dana A. Shea, “Terrorism: Background on Chemical, Biological, and Toxin Weapons and Options for Lessening Their Impact,” Congressional Research Service, 2004.

[4] T.V. Paul, “Taboo or Tradition? The Non-Use of Nuclear Weapons in World Politics,” Review of International Studies 36 (2010): 853-863.

[5] Jeffrey Fetter, “Psychosocial Response to Mass Casualty Terrorism: Guidelines for Physicians,” Prim Care Companion J Clin Psychiatry (2005) 7(2): 49-52.

[6] Robin Wright, “Iran Still Haunted and Influence by Chemical Weapons Attacks,” Time Magazine, January 20, 2014, accessed February 16, 2016,

[7] Ibid.

This article was originally published in the Georgetown Security Studies Review.