U.S. intelligence has detected increased activity at Syrian chemical warfare facilities, raising concerns about the regime potentially using chemical weapons (CW) against the opposition. Although such an action would likely only be carried out in extremis, Bashar al-Assad and his cohorts are approaching that very status. Given the regime's lack of regard for the casualties it has already inflicted and the value it places on its own survival above all else, the United States must prepare for the growing possibility of CW use in Syria.
WHY NOW?
After twenty months of internal war, the regime is in an increasingly difficult military situation. It suffered substantial reverses in November, losing territory, positions, troops, and equipment, including combat aircraft. The fighting capacity of its forces appears to be diminishing, and its standard tactic of bombing and shelling opposition areas, primarily civilian, is becoming less effective and more costly due to rebel antiaircraft fire and other tactics. As a result, pressure is undoubtedly rising within the regime to take different and more effective action -- that has been the pattern for Damascus since the emergence of armed opposition in summer 2011.
THE REGIME'S CHEMICAL ARSENAL
Syria has a formidable CW capability. Its large inventory reportedly includes the nerve agents sarin and possibly VX, as well as mustard gas, a blister agent. Means of delivery include aerial bombs, missiles (e.g., Scuds), and artillery shells and rockets.
The Syrian military is trained to use these weapons and has the doctrine, forces, and munitions to carry out such attacks. These forces can reach anywhere in the country, and there is very little the opposition Free Syrian Army could do to stop them. Without intelligence warnings from external sources, rebel combatants and civilians would be highly vulnerable to surprise chemical attacks, increasing the chances for major casualties.
CW SCENARIOS
The regime could use chemical weapons in a variety of ways, from a limited or demonstration attack to large-scale offensive or defensive use to fundamentally change the military situation. At present, reports that the regime is weaponizing relatively small quantities of agent suggest the former. Limited CW use could be controlled better in terms of effects and visibility. The regime might also find it easier to explain away small-scale strikes as the work of "terrorists" or as a justifiable response to the military situation and the threat to the country.
One form of limited attack could be a strike against a specific military target, aimed at affecting a local but important tactical situation. Such an attack would also demonstrate that the regime was ready, willing, and able to carry out such actions.
The regime could also conduct small-scale strikes on civilian targets to intimidate the population or punish them for supporting the rebels. This would be an escalation from the regime's routine use of explosives and incendiary weapons against civilians and could produce substantially greater casualties. It would undoubtedly have profound psychological effects on an essentially defenseless population.
As for broader CW use, the regime could employ such weapons to support ground offensives in key areas where its forces have been unable to achieve success via conventional tactics (e.g., around Maarrat al-Numan in Idlib province; in and around Aleppo city; in Deir al-Zour province, perhaps near Abu Kamal or Mayadin). It could use them to support defensive operations in places where rebel forces are on the offensive (e.g., the relatively remote Raqqa province) or have regime forces surrounded (as happened at the 46th Regiment base near Atareb in Aleppo province and the artillery fire base at Mayadin; in both cases, the positions fell to the rebels after prolonged siege and final assault). Using CW in close proximity to its own forces would be risky, but the military has some chemical defense equipment and training and might be able to provide a measure of protection.
The regime could also use persistent CW agents for area denial, striking lines of communication, shelters, and medical and food facilities to prevent rebels and civilians from using them. Finally, local military commanders operating independently of the government could decide to use CW on their own, whether out of revenge, frustration, fear, or other motivations. This would of course depend on access to munitions and delivery means, but in conditions where units are isolated or the chain of command is breaking down, such use is possible.
REGIME CONSTRAINTS
Unfortunately, the international community's track record so far may have given Assad a bad lesson regarding the potential consequences of CW use. The regime's massive escalation of violence throughout the war -- including use of field artillery against civilians, aerial bombing of population centers, and routine use of cluster munitions -- has gone largely unpunished, and Damascus has likely concluded that raising the stakes even higher would carry few real repercussions. It may therefore believe it can get away with limited CW use.
In theory, various political constraints could deter the regime from such a course. These include a likely irreparable break with the country's entire Sunni population, a probable rupture in relations with China and Russia, and great embarrassment for its allies Iran and Hizballah. More important, CW use would probably mobilize the West and Sunni Arab states to directly intervene in the conflict, sealing the regime's fate. Additionally, all those involved in ordering and carrying out CW attacks would risk international judicial action -- a prospect that could spur some regime members to mount a coup. Finally, the regime would have to deal with the massive public relations disaster that CW use would bring.
There are also military constraints. Chemical weapons are not just another device that can be pulled from storage and fired -- regime forces must also consider accuracy and reliability issues, meteorological factors (wind, humidity, temperature), agent choices (persistent vs. nonpersistent), and consequence-management issues (treatment of casualties, force protection, decontamination).
IMPACT OF CW USE
If the regime does decide to use chemical weapons, it could have significant effects on the military situation. The rebels have no protection against CW and no training to deal with such weapons; they barely even have experience with the effects of riot-control agents and smoke. They would be highly vulnerable, and the regime could achieve tactical or broader gains.
Politically, CW use could weaken the opposition, undermining the all-important link between the civilian population and the armed rebels. The significance of this deterioration would depend on the resilience of the population, which so far has proven steadfast in the face of all regime attacks.
There would also be humanitarian consequences, including probable refugee flows out of affected areas, the need to treat casualties, and decontamination requirements. The ability of NGOs and humanitarian groups to continue operations in such conditions would be tested.
CONCLUSION
Yesterday, President Obama reiterated that the United States would not accept the use of chemical weapons by the Syrian regime, and that there would be consequences for such use. Although Washington issued similar warnings in the past, the situation has changed, and the administration must be prepared to have its declaration tested. CW use is by no means a given, but the potential has gone up substantially and will grow as the regime's fall comes closer.
Upholding the U.S. declaration requires readiness to commit armed forces to eliminating Syria's CW capability and punishing the regime and its forces for using them. It means having military assets earmarked or in place to act quickly with overwhelming force, and to deal with the post-attack environment. It does not mean relying on diplomacy as the sole or even main response. Failure to respond with force to any use of chemical weapons would be dire. The regime would see it as a signal to conduct more attacks, and the opposition would see it as a complete abandonment.