One of the main arguments against US missile strikes to punish Syria's
regime for its alleged use of chemical weapons is that such attacks will be of
little immediate use in protecting civilians. This is only one aspect of the
debate: others center around whether strikes are likely to lead to a stable
negotiated ceasefire , or whether they will deter
use of chemical weapons in future conflicts, or whether they fit American
strategic interests. But it is an important one: the question of whether
strikes will have a direct impact on civilian deaths in Syria is a key
component of their legality under the Responsibility to Protect doctrine.
A study published by the Journal of Peace Research currently making the rounds suggests that external intervention in civil wars is actually likely to increase civilian casualties. War is unpredictable, which makes comparative studies of this sort that show general patterns extremely valuable. But any set of comparisons will have outliers. Syria’s differences from most civil wars, and the unusual nature of the proposed intervention, show how strikes -- if they can deter future chemical weapons use -- might not fit this pattern.
The differences are:
1) Chemical weapons are used extremely rarely in war. When they are used in populated areas, they are disproportionately deadly to civilians
2) In Syria, unlike many civil wars, the rebels control large swathes of territory and government forces are extremely circumscribed in their movements
3) Syria is already seeing large-scale external intervention by President Bashar al-Assad’s allies
Firstly, chemical weapons are a devastating but haphazard way of making war. Civilians can often take cover from conventional artillery, even if fighters actively defending an area cannot. Chemical weapons on the other hand are silent, disperse over a large area, seep into places like basements which provide shelter against other sorts of attacks, and linger, killing rescue workers and others who enter contaminated zones, either by accident or necessity. (Reportedly, all but one of the activists who rushed to document the Ghouta attack died doing so.) The deadliest conventional artillery bombardments in Syria’s war, such as those that struck Homs in February 2012, usually killed 50-100 people in a day. The low-end estimates of the Aug. 21 strikes in Ghouta outside Damascus are around 400-500 dead, and the US estimate runs over over 1,400. Many writers have pointed out that, even if strikes deter chemical weapons use, artillery and airstrikes will continue to kill civilians. They will, but about five to ten times less efficiently.
Secondly, the military stalemate in Syria’s civil war makes some kinds of killings of civilians less likely, and some kinds more likely. Most civil wars are relatively fluid: either territory changes hands, or the weaker side is small enough and mobile enough to enter territory controlled by the stronger side. The weaker side has an incentive to use fear to force civilian populations with divided loyalties to comply with them or to keep their whereabouts secret. The JPR study suggests that when intervention tips the balance for one side, the other's incentive to use terror increases.
Syria, however, is at this stage an unusually static civil war -- particularly for the government. It has lots of heavy weapons but limited infantry, and is probably outnumbered by Syria’s highly decentralized rebel forces. The government generally knows where to find the rebels; it just can't always hit them. The rebels usually have the sympathy of civilians in the areas where they are entrenched. In the last year, territory has changed hands very slowly, usually requiring months-long sieges. Government forces generally prefer to stand off and bombard areas with artillery or airpower, and chemical arms dramatically increase the amount of deaths that they can cause over time. Of any recent civil war, this military situation is perhaps most comparable to Bosnia, where US airstrikes against Serbian artillery were effective in reducing civilian deaths.
Thirdly, the JPR study argues that civilian deaths spike when a local balance of power is upset. The Syrian civil war’s balance has already been tilted in recent months in the government’s favor by Russian and Iranian arms transfers and an influx of Hezbollah fighters to make up for its infantry shortcomings, allowing it to retake some rebel enclaves. While rebels can still besiege and capture isolated bases deep within their territory, it is unlikely that they will be able to make lasting gains in territory where support for the government is strong. A limited US strike if anything will tip the war back toward equilibrium.
If the government feels comfortable using chemical weapons on a large scale, on the other hand, this would be a new element that could change the pace of the war. Assad cannot end the conflict -- he doesn't have the troops to occupy all the small towns of northern Syria with large enough garrisons that they cannot be overrun. But attacks on the Damascus suburbs or rebel-held parts of Aleppo may kill many thousands who might otherwise have survived the war, while sending tens of thousands more fleeing from their homes and leaving behind depopulated cities for the government forces to recapture, opening up new relatively secure rural areas to attack.
The question remains as to whether US strikes can deter large-scale chemical use. Syria until now has not made full use of its arsenal -- most previous alleged attacks were on a small scale, and even the Ghouta strike seems to have made use of water-down chemicals and homemade munitions in an apparent attempt to muddy the evidence and prevent a smoking gun. This suggests that Assad was somewhat deterred by Obama’s “red line” declaration, but not so deterred that he didn’t decide to push the envelope. A strike that costs Assad less than it benefits him to use chemicals, or one that has such a messy aftermath that Obama is unlikely to strike again in the future, may well embolden the regime to use chemicals more often. But so could doing nothing at all.