With Turkey’s decision to shell targets in Syria in retaliation for a mortar attack that killed five civilians inside the Turkish border, there are new signs that Syria’s civil war could escalate into a broader conflict.

As the stalemate continues on the ground, the cross-border clashes may put added pressure on the West to heed the calls of Syrian rebels and their international backers, including NATO ally Turkey, for a partial no-fly zone.

While the desire to act to prevent Syria’s conflict from spilling over borders and provide safe haven for the tens of thousands who continue to flee the repressive regime of Bashar al-Assad is understandable, the scale of such an operation is bound to be much larger than its proponents have suggested.

I conducted an open-source analysis to estimate the requirements for establishing command of the air over Syria. The study shows that the effort could require about 200 strike aircraft and more than 100 support aircraft for only the first waves of strikes, making a Syrian intervention many times larger than the opening phase of NATO’s recent air war over Libya.

After that, there is a high probability that the operation would develop into providing close air support for rebel forces. This new phase of the military operation would require a further escalation of force numbers and resources.

Frustration is understandably rising as the Assad government remains stubbornly in place after 18 months of bloodshed. With the U.S. reluctant to embark on another military adventure in the Arab world, interventionists have pressed for a partial no-fly zone between Aleppo and the Turkish border. This would enable the creation of a safe zone in that area where humanitarian aid could be delivered to civilians fleeing the Syrian military’s brutal counterinsurgency campaign, an operation that has included the use of indiscriminate shelling.

A U.S.-backed intervention along these lines, most recently advocated by Qatar and NATO allies France and Turkey, would unfold in two major phases. The first, establishing a no-fly zone, would require a sustained effort to degrade Syrian air defenses in order to achieve command of the air.

While dense and overlapping, Syria’s strategic air defenses present few serious challenges for Western air power. Most of the equipment consists of aging Soviet-designed surface-to-air missile systems that NATO either destroyed or countered with relative ease in previous interventions over Kosovo and Libya. Because many of these older systems are relatively immobile, it is likely they could be eliminated quickly using an initial barrage of cruise missiles launched from naval vessels in the Mediterranean, in combination with an early wave of air strikes.

But the Syrian systems have recently been augmented with more advanced and capable Russian designs, including the Buk-M2E and Pantsyr-S1. These and other mobile air defenses pose a larger threat. Should Syria’s mobile air defenses survive initial strikes, they could quickly complicate efforts to use air power to defend a safe zone from attacks by Assad’s ground forces.

Recent upgrades to U.S. aircraft targeting systems may mitigate these concerns, but Syrian air defense operators might still find ways to pose persistent risks to coalition aircraft. If so, they would hamper efforts to locate and hit ground targets and might make any campaign much longer and slower than interventionists anticipate.

Blowing down Syrian air defenses is just the start. A no- fly zone would also require destroying enough of Syria’s most capable combat aircraft on the ground to deter Syrian pilots from challenging the zone.

My study found that initial strikes would require destroying more than 450 targets, including at least 22 early warning radar sites and command-and-control facilities, 150 surface-to-air missile batteries, 27 surface-to-surface missile batteries, 12 anti-ship missile batteries, 32 airfield targets and more than 200 hardened aircraft shelters. This could require dropping more than 1,600 munitions over hundreds of sorties in the opening days of strikes, and could drag on much longer should mobile targets prove difficult to find, which is all but guaranteed.

Advocates of a partial no-fly zone imply that a lesser effort would be required. But even enforcing a limited zone would necessitate targeting air defenses, command and control facilities, and airfields as far away as south of Damascus due to the range of some of Syria’s static air defenses. If coalition aircraft were later called upon to support a rebel offensive as in Libya, a total no-fly zone encompassing all of Syria would rapidly be required.

In the second phase, establishing a northern safe zone would require delivery of humanitarian supplies over the Turkish border. But Assad’s ground forces would almost certainly contest the zone using the 1,980 artillery pieces, 500 rocket launchers, and hundreds of mortars at their disposal. These weapons contribute to the large advantage in firepower Assad’s forces currently enjoy over the rebels. They would surely be used against a safe zone, were it believed tactically expedient, since the government would see the area as a launch pad for the rebel military.

If so, a more robust effort would be needed to protect civilians and aid organizations. Having declared the region a safe zone, the burden would fall on coalition aircraft. This would require moving beyond keeping Syrian aircraft out of the sky to targeting pro-regime ground forces directly and on a sustained basis.

While rebel forces are substantial, they remain fragmented. Interventionists hope a safe zone will provide a base for them to organize. But if rebels struggled to form a cohesive force capable of offense, pressure to escalate to strategic bombing against regime targets in Damascus would become intense. What started as a limited humanitarian operation in the north would end with the West playing the role of rebel air force: this time all the way to Damascus.

Stalemate will inevitably produce wider calls for intervention. But for outside powers seeking to end Syria’s civil war, there is no limited option. 

By Brian T. Haggerty

Brian T. Haggerty is a doctoral candidate in political science and an affiliate of the security studies program at the Massachusetts Institute of Technology. The opinions expressed are his own. ― Ed.

(Bloomberg)