While Syria has been upgrading its aging defense system in recent years, it will be severely tested if a barrage of American-made missiles are fired at the country. The question is, How will Syria fare?
Syria boasts an integrated system that covers much of the most populous and strategic parts of the country. But is all that hardware in working condition after two and a half years of war? Does the Syrian military have the manpower and expertise to run the system, or is it stretched thin by the conflict? Can Syria still deploy blanket coverage since there are now pockets of the country out of its control? Did Israel's strike inside Syria this year reveal Syrian vulnerability?
Russia's Interfax news agency quoted a confident, if unnamed, "military diplomatic source" on Tuesday who predicted "no easy victory" if "the U.S. Army together with NATO launches an operation against Syria. Buk-M2E multirole air and missile complexes and other air defense systems are capable of making a fitting reply to aggressors."
Experts aren't so sure.
What Does Assad Have?
Estimates by the International Institute for Strategic Studies (IISS), Jane's and the Center for Strategic and International Studies (CSIS) of Assad's pre-war defense capabilities included 365 to 550 combat aircraft (50% of which CSIS estimates may be left now with questions about pilot capability); 25 air defense brigades with some 120 to 150 surface-to-air missile batteries (most aging or obsolete); and an array of more modern short-range surface-to-air weapons, including thousands of shoulder-launched MANPADS.
Syria has purchased a highly advanced S-300 system from Russia, which can intercept targets at a much longer range and higher altitude than anything currently in Syria's arsenal. But it hasn't been delivered yet, and even if it arrived tomorrow, it would take months to set up and properly train Syrians to use.
One of the Syrian military's most potent assets are its Bastion coastal defense missiles, which Assad bought from Russia in the last few years. They could strike ships in the Mediterranean and would effectively push back the distances from which foreign ships would launch missiles used in any attack. Part of the system are Yakhont anti-ship missiles, which were reportedly Israel's target when it bombed a Syrian depot in July.
According to Sean O'Connor, a Jane's contributor and expert on air defense systems, the surface-to-air batteries and radar sites throughout the country provide overlapping coverage throughout most of the territory, though the system remains more vulnerable in its eastern half. He noted, however, that the Soviet-era systems are vulnerable to complex attacks because each one can only engage a single target at a time.
How Well Could Syria Defend Itself Against U.S.-Led Attack?
Experts agree that Syria's defenses are much larger, better deployed, more advanced and much better trained than Libya's, which the U.S.-led coalition quickly obliterated. Experts also agree the U.S. would still be able to take them out, albeit with significant firepower. Tony Cordesman of CSIS, writing in May about the possibility of enforcing a no-fly zone (not what the U.S. and its allies are said to be leaning toward now) suggested, "It would take a massive U.S. air and cruise missile attack to suppress it quickly."
O'Connor believes the easiest way to do that would be to send a barrage of missiles aimed at the radar sites. "Such a strike would represent a comparatively low-cost and low-risk method of greatly reducing the threat posed by the network," he told ABC News.
"The Syrian IADS (integrated air defense system) is not capable of defeating a large-scale attack by a modern air arm. The overreliance on aging technology, technology often encountered and exploited by Western air arms, puts the overall network at significant risk," he said.
Syria has also tried upgrading its aging Soviet systems by integrating newer Chinese radars and sensors, but O'Connor says it remains to be seen how well they mesh.
Cordesman says the system has other vulnerabilities. "They also have aging surface-to-air missiles (SAM) that have been only partially upgraded and are vulnerable to jamming and other electronic countermeasures, as well as antiradiation missiles," he wrote.
Has the War Taken a Toll on the Syrian Air Defenses?
On this point experts remain divided, largely because it's very difficult to tell from afar. Pieter Wezeman, who tracks arms shipments at the Stockholm International Peace Research Institute (SIPRI), says that Assad began stocking up on modern defense systems in around 2010 and Russia has continued to deliver components throughout the conflict. But he also points to reports that rebel forces have been able to capture military bases where some systems were stored, though it's unclear if those systems were old or outdated.
"On the basis of that I would expect there to be major gaps in the Syrian air defense system," he told ABC News by email.
"Current operations by anti-government forces have had little impact on the overall network," he said, noting that the bulk of surface-to-air systems remain in Assad-controlled areas.
He said crew readiness probably wouldn't be an issue either because those groups haven't played much of a role in the conflict thus far. The rebels, of course, have no planes to defend against.
Cordesman pointed out in May that the fact that Israel was able to hit targets inside Syria may be a sign of how the country's air defenses have degraded. But he also cautioned, "At the same time, this does not mean that Syria could not put up a defense or that the U.S. could simply rely on a few strikes or threats to either destroy Syria's air defense or intimidate it into complying with U.S. demands."
It's unclear how far into Syria Israeli planes had to travel to conduct the bombing, or if they did at all, and how much effort Syria took to stop them, knowing it was only a limited attack. Some believe Israel may have lobbed the bombs over the border, rather than entering Syrian airspace and risking being shot down.