The increasingly bloody civil war in Syria has raised concerns that the regime of Bashar al-Assad will eventually use its stockpile of chemical weapons (CW) against armed oppositionists and civilians or that insurgents and terrorists will get their hands on them. Indeed, in light of recent opposition gains, unless the United States reaffirms and strengthens its previous deterrent warnings, the Assad regime is liable to use CW against its own people, with catastrophic results for Syria and its neighbors.
Syria's CW arsenal is believed to be the largest in the region. It has reportedly produced artillery rockets filled with the blister agent mustard, as well as aerial bombs and missile warheads filled with the nerve agents sarin and perhaps VX. Despite the reputed size and sophistication of this stockpile, it is unclear at this point that the Assad regime could kill many more insurgents or civilians with CW than it is already killing by conventional military means -- though CW has the potential to sicken or injure many thousands and to induce new, even larger refugee flows.
Iraq's use of CW during the Iran-Iraq War showed that large concentrations of agent are generally required to cause heavy loss of life, though even small amounts can injure thousands. Some 10,000 Iranians, half of them civilians, were killed by CW during eight years of war (around 5 percent of the total number of Iranians killed during that conflict), and another 50,000 suffered moderate to severe injuries. More than 45,000 Iranians continue to suffer the long-term health effects of exposure to chemical agents, including skin, eye, and respiratory ailments, birth defects, cancer, and post-traumatic stress.
Two of the best-known Iraqi chemical attacks on civilian targets are the bombings of the Iranian town of Sardasht in June 1987 and the Iraqi Kurdish town of Halabja in March 1988. In Sardasht, Iraqi aircraft dropped seven 250-kilogram bombs filled with mustard, killing about 100 people and injuring 4,500. In Halabja, more than 50 aircraft dropped some 200 bombs filled with mustard and nerve agents, killing some 5,000 immediately and injuring thousands more.
It took Iraq several years of trial and error before it was able to effectively employ chemical weapons on the battlefield, and its successes were due in part to the fact it used them against human wave attacks and troop concentrations -- ideal targets for chemical weapons. Syria lacks this experience, and the armed opposition tends to operate in relatively small, dispersed formations. Moreover, Syria may lack sufficient artillery and air power to deliver the type of concentrated, sustained bombardments that produce the kind of mass casualties experienced in Halabja and during combat in the Iran-Iraq War. (For instance, Syrian government airstrikes rarely involve more than a lone aircraft against a single target.) And it may initially use CW in a measured fashion, in ways that could be difficult to verify, in order not to provoke an American military response.
Thus, Syria could probably kill many scores of people in individual chemical strikes -- about as many as it has killed in recent conventional airstrikes on gas stations and bakeries -- and produce thousands of casualties that would need immediate medical attention as well as long-term care. While such strikes are unlikely, in the long run, to fundamentally alter the military balance between the Assad regime and the armed opposition, their psychological impact could be devastating, leading to mass refugee flows into neighboring countries and a humanitarian crisis of massive proportions.
For these reasons, the United States has an overriding interest in deterring the use of chemical weapons by the Assad regime. Accordingly, U.S. warnings of unspecified "consequences" in response to the use of CW need to be sharpened with a threat to use force, backed by the deployment to the region of additional strike aircraft to make this threat credible. Should deterrence fail and should the United States want to disrupt the regime's use of CW (or prevent its diversion by others), it has a number of military options. It could seek to deny access to CW stockpiles by collapsing the structures where they are stored -- or rubbling their entrances -- using reduced-yield bombs, such as the BLU-126/B, and then seeding the area with antipersonnel bomblets or mines. Or it could create a low-grade contamination hazard around CW storage sites by destroying a few munitions using the nonexplosive CBU-107 passive attack weapon (which disperses thousands of tungsten penetrator rods that could punch small holes in bulk storage containers or munitions), thereby hindering access to the area. Or it could use agent-defeat munitions, such as the BLU-119/B, to incinerate CW agents.