As the killing of civilians escalates in Syria, diplomats at the U.N. Security Council are grappling with a vexing issue: If they demand that Syrian President Bashar al-Assad step down, and Assad thumbs his nose at them, what then?
At issue is a resolution backed by the United States, Britain, France, the Arab League and others, that insists that al-Assad not only stop the violence against his people, but give up power within 15 days -- or else. The "or else,'' according to the resolution, is that Assad would face unspecified "further measures.''
In fact, the world outside Syria has little leverage to bring the Syrian crisis to a quick close. And if Assad declines to give up, as seems likely, officials say there are virtually no military options that the United States and other backers of the resolution can wield to back up their rhetoric with force. The resolution itself, in wording crafted to seek the support of Russia and China, explicitly rules out force, for now.
As a result, the increasingly violent revolt against al-Assad's rule is likely to stagger on inconclusively, analysts say, leaving civilians in rural villages and poor urban neighborhoods, where the uprising is centered, to face the heavy weapons of the Syrian army. Through January, the U.N. said, at least 5,400 civilians have been killed.
And with the Syrian army largely intact, the uprising against Assad "has reached an impasse that is unlikely to be broken by the United Nations Security Council,'' concludes a veteran Syria-watcher, Yezid Sayigh, a senior associate at the Carnegie Middle East Center in Beirut.
No recent U.S. military operation -- not peacekeeping in the Balkans or a Libya-style no-fly-zone or an outright invasion and occupation -- offers an acceptable model for intervening in Syria's sectarian violence, according to U.S. officials and outside analysts.
Worse, what few theoretical options for military intervention do exist carry enormous risks and potentially explosive repercussions not just inside Syria, but across a heavily armed and unstable Middle East. Russia, the United States, Hezbollah and Hamas, and Iran and Israel are all jockeying for advantage, while Egypt and Iraq are gripped in political struggles, and the U.S., Israel, Europe and Iran are veering toward conflict over Iran's nuclear weapons program.
Syria's military, armed and equipped by Russia and Iran, is large and powerful -- at least on paper -- with massive tank forces, a large air force and extensive networks of air defenses. And Syria boasts one of the largest arsenals of advanced chemical weapons in the Middle East, with stockpiles of mustard gas and the nerve agents Sarin and VX, as well as the missiles, rockets and artillery shells to deliver them, according to the Nuclear Threat Initiative, an independent organization that monitors global weapons of mass destruction.
But Syria's army is also manned largely by conscripts, and its MiG-29 and SU-24 aircraft are poorly maintained. Most of Syria's air defense radars and missiles are outdated and vulnerable to attack, according to Anthony Cordesman of the Center for Strategic and International Studies, a nonpartisan Washington think tank.
Despite a steadily increasing flow of lower-ranking desertions, the Syrian military has stayed intact during the conflict. No major units have defected to the rebels and the army retains the ability to maneuver at will, analysts said. Russian ships recently unloaded ammunition and several batteries of an advanced air defense missile, the BUK M2E, at the Syrian port of Tartus.
"The military has not turned against Syria's president,'' writes Joshua Landis, director of the Center for Middle East Studies at the University of Oklahoma. The army, he points out, has the heavy weapons. And al-Assad has packed its top ranks with fellow Alawis and Baathists, likely to remain loyal against a popular uprising of Sunnis.
Although opposition leaders inside Syria have not asked for outside military intervention -- a step they feel the regime would use to justify a harsher crackdown -- outsiders have suggested that western military forces could establish and defend a "humanitarian corridor'' into Syria from Turkey. It could be used to provide logistical support to opposition forces and to enable refugees to flee to safety. Others have suggested establishing "safe zones'' inside Syria as protected sanctuaries for opposition civilians and fighters.
Either option would require a no-fly zone, and that, analysts say, is unworkable. As with Libya, it would require days or weeks of air strikes against the air defense facilities and other defenses. Once established, U.S. or allied aircraft would find few targets: the al-Assad regime does not often use aircraft against the Syrian opposition. Unlike Libya's vast desert spaces where military vehicles could be identified and attacked, Syria is densely populated, and much of the fighting is concentrated in urban neighborhoods where it would be difficult to target loyalist forces without causing civilian casualties.
But the strategic repercussions of any U.S. military intervention are as scary as the prospect of American forces meeting up with Syrian nerve gas.
It is a dangerous and unstable neighborhood, with powerful forces seemingly intent on using the Syrian conflict to maintain or increase their leverage in the region. Syria is a long-time client state of Russia, which has used its influence there as a foothold in the region and is a staunch backer of the al-Assad regime. Russian warships rotate in and out of the port of Tartus, just as the U.S Navy makes regular port calls in Israel. Iran has also used Syria as an additional power base, helping to arm both Syria's military and the Islamic extremist group, Hezbollah, in neighboring Lebanon.
If the Assad regime begins to crumble, "the more Hezbollah -- and its backers in Tehran -- will view the Syrian crisis as an existential struggle designed to deal them a decisive blow,'' writes Arbour, of the International Crisis Group of independent analysts. "And the greater the risk that they would choose to go for broke and launch attacks against Israel in an attempt to radically alter the focus of attention."
Rising tensions over Iran's nuclear weapons program are inextricably entangled in the Syrian crisis as well. Sharp disagreements between the United States and Russia over Iran sanctions and missile defenses are likely to be inflamed anew over Syria, even as Israel weighs a strike against Iran's nuclear production facilities.
If there are no good military options for the United States in Syria, there are risks as well in simply standing by as the conflict escalates into an all-out civil war, as James Clapper, director of national intelligence, told the Senate Intelligence Committee Tuesday.
Most immediately, Clapper said the conflict in Syria is not likely to be resolved quickly, and the longer it goes on, the more favorable conditions are created for terrorist groups.
"Prolonged instability ... and ongoing unrest most likely would exacerbate public frustration, erosion of state power and economic woes,'' he said, "conditions that al Qaeda would work to exploit.''