This is the strongest call for foreign military intervention that has yet come from the international community regarding Syria, as more and more Syrians are getting caught up in government crackdowns and increased fighting between the Syrian army and a growing armed opposition movement. Yet questions about the nature and timing of such an intervention are far more complex than in Libya.

As Rania Abouzeid put it simply in Time, “Syria is at war.” A leaked report from the Arab League’s now-defunct fact-finding mission to Syria notes that the situation is rapidly degenerating into a contest between government forces and a growing, determined guerrilla movement (simply called the “armed entity”) that formed due to “excessive use of force by Syrian Government forces, in response to protests that occurred before the deployment of the Mission demanding the fall of the regime.”

“In some zones, this armed entity reacted by attacking Syrian security forces and citizens, causing the Government to respond with further violence,” wrote the observers. “In the end, innocent citizens pay the price for those actions with life and limb.”

This is what makes the newest argument for intervention advanced in the United States so troubling. The prospect of heavily armed militias fighting the government (and perhaps each other) is known. But for some U.S. politicians, this is acknowledged and seen as an acceptable risk. Some members of Congress are now advocating arming the anti-regime militias, suggesting that if better equipped, the militias could hold back (perhaps even defeat) Assad’s forces. The U.S., EU, Turkey, Libya and Saudi Arabia are looking for Assad’s departure (Israel’s interests are still unclear), while Russia, Lebanon and Iran appear willing to provide support for Assad. In short, the potential for proxy intervention has definitely increased since the UN failed to pass a resolution against Assad last week.

Joseph Lieberman and John McCain were the first to make such calls, and have been joined by other members of Congress in the past few days. Now a bipartisan group of senators is advancing a resolution calling for “the President to support an effective transition to democracy in Syria by identifying and providing substantial material and technical support, upon request, to Syrian organizations that are representative of the people of Syria.” It does not elaborate on who these groups are, or what constitutes material and technical support, but at the very least, it would mean financial assistance (which the militias could use to purchase arms on the black market) and intelligence dissemination, which would almost certainly result in the dispatch of military observers or advisors.

This approach is a gamble. So too are suggestions for creating no-fly zones over northern Syria, or counting on sanctions and brokerage by the Russian foreign minister to achieve a political solution. Any form of intervention or non-intervention will cost lives – lives that could have been saved, lives that might not have been lost. But of those options, the call to arm militias, or cooperate with them by providing Western funds and intelligence (which would likely be channeled through the Turks and Saudis), is more likely to become a reality since the United States could act without relying on the UN.

If this is just talk meant to encourage the opposition and scare Assad, then it runs the risk of achieving one, but not the other (and of falsely raising the hopes of the groups we’re ostensibly supporting, as happened in Iraq in 1991). If implemented, there are risks that the disbursement of arms will bring stalemate, not solution. Writes Syrian blogger Maysaloon, “we might see a drastic arming of the Free Syrian Army, and an escalation of the conflict to a fully blown civil war. If that happens I wouldn’t be surprised in the slightest if the Russians (and Iran) continue to arm Assad to the gills.”

“I don’t think anybody, apart from Assad, would want to see that happen,” Maysaloon believes. “Of course Assad would prefer this solution because it would justify his oppression and use of violence, and also extend the period of his rule.”

The program could actually lead to more direct foreign military intervention. Even should the militias succeed and Assad falls, nothing suggests that all of these now well-armed groups would lay down their arms. And who would secure the Syrian Army’s depots to prevent a militia from grabbing a few truckloads of munitions from an unguarded arms cache, as has happened in post-Saddam Iraq and post-Gadhafi Libya?

Additionally, the Alawites of Syria, as the Economist notes, have their own militias with access to the regime’s weapons stockpiles. Alawites and Christians are overrepresented in the officer corps, so even if many do abandon their posts, they are not likely to abandon their arms – especially given what happened next door in Iraq and Lebanon since the 1980s. They would be loath to do so; and so too would the victors fearful of an insurgency by unrepentant Baathists. It is worth remembering that the first insurgents the US faced in Iraq were ex-Iraqi army guerrilla cells, and soon Sunni and Shia communities were taking advantage of unsecured weapons to arm themselves, both in self-defense and for reasons of revenge.

Whether one supports intervention or not, past experience suggests that an international peacekeeping force would be required to secure these depots, which essentially defeats the purpose of arming the militias as an alternative to direct intervention. Such a force would also be necessary to ensure that the militias – including the pro-Assad ones – are turning in their arms and keeping to cease-fire agreements. Otherwise, Syria might end up in a scenario where many in the officer corps retain their arms, the arms depots are thrown open to everyone, and community self-defense becomes blurred with ethnosectarian revanchism.

And then there is the matter of border control, especially with respect to Lebanon and Turkey, as it’s clear that arms smugglers, refugees and militiamen are already easily moving across these borders. An enclave of militias and refugees has formed on the northern Syria-Lebanon border, and clashes between pro- and anti-Assad militias have reportedly occurred on the Lebanese side of that border.

The armed opposition is gaining, but also losing, ground throughout the country. The government’s brutal crackdowns have produced groups taking up arms to defend themselves, and also to take the fight to Assad. Paul Wood of the BBC says that the country is witnessing “an escalating guerrilla campaign” – one echoing the struggle between the regime and the Muslim Brotherhood between 1976 and 1982 – and that the “Free Syrian Army” (FSA) claims to be planning a “general offensive” in response to the government’s siege of Homs, even though the government is closing its iron ring around the city.

Nic Robertson at CNN reports that in Homs, the epicenter of the opposition, the local opposition council “is not the only show in town. Salafists are moving in too, Islamic radicals … Reports abound of infighting both inside and outside Syria, the hard-liners already jockeying for post-al-Assad power.” Al Qaeda in Iraq (AQI), now allegedly operating in Syria to provoke further strife between Assad and the Syrian opposition, views Syria as a prize to be won, as do other jihadists throughout the region.

A split remains between the Syrian National Council (SNC), the most visible Syrian opposition group, and the FSA, the umbrella name for the various anti-regime militias that are now active in Syria. And while the SNC is increasingly recognized as the international voice of the opposition, it too has struggled to reach a consensus on foreign military intervention. The SNC is conspicuously absent from a “dialogue” with Assad that the Russians are trying to promote as an alternative to the UN resolutions they’ve vetoed. The SNC says it has been excluded on purpose. The Russian Foreign Ministry, for its part, has shown disdain for the SNC and a clear preference for Assad retaining power.

The Economist presents an overview of the domestic forces still supporting Assad, which shows that for the most part, “support” means acquiescence to his rule out of fear. Syria’s sectarian divides are sharpening in response to such fears of “Sunni triumphalism,” says the Economist – and Assad’s propaganda machine is playing these fault lines up. According to Patrick Seale, many poor Sunni youths were at the forefront of the nonviolent demonstrations that were suppressed. After years of limited opportunities, and in response to the government’s actions, they are now taking up arms against the regime.

As the violence mounts, pent-up grievances are coming to the fore and the unarmed majority is losing patience – but with whom, the government, or the emerging militias? No one can say for sure, or predict how more and more unarmed people in communities targeted by the government for repression (and by the opposition for liberation) will react as the violence continues. The only thing that can be said with certainty is that geopolitical maneuvering is rapidly eliminating any prospect of a “third way” that does not end in a proxy war, or a regional conflagration.

Syria is a unique case. Unlike Libya it doesn’t have a lot of oil. Unlike Egypt, it is not controlled by a U.S.-funded ally. What it does have is an increasingly violent dictatorship and a growing but divided opposition. The government of Bashar al-Assad shows no signs of weakening resolve, and Arab League monitors in the country have drawn criticism (and live fire) for their work.

The Syrian National Council, which is dominated by Syrian émigrés in Turkey and Europe, has reiterated its calls for foreign military intervention despite contradictory remarks from some of its members. The SNC wants to establish a no-fly zone over northern Syria to provide a safe haven for refugees and the loosely organized “Syria Free Army” in preparation for NATO and Arab League-backed operations against Assad’s loyalist forces.

The National Coordination Body, composed of left-wing Syrian Arabs and Kurds operating inside Syria, continues to warn against foreign intervention and expansion of armed resistance to Assad.

The unity agreement’s collapse — and reports suggesting that a majority of the Syrian opposition and demonstrators now favor foreign military intervention — may help strengthen the hands of those in the West who have argued for such action from the beginning.  In Washington a “time-limited, scope-limited military action” as implemented in Libya this past year appeals to both Obama administration policymakers who say they are guided by a “responsibility to protect” and to neoconservatives who favor “regime change” in Damascus to isolate Iran and Islamist groups.

The SNC consists of representatives from seven factions, according to former French diplomat Ignance Leverrier, including “the local coordinating committees organizing resistance on the ground in Syria; the Muslim Brotherhood (which was banned by Syria’s secular opposition parties in the Damascus Declaration); ‘independents’ who belong to no political party; technocrats; the Kurds; and the [Bedouin] tribes.”

Leverrier, who supports recognition of the SNC as Syria’s legitimate government, says the council is better-informed and more representative of popular opinion than the National Coordination Body. He acknowledges, though, that the council is led by  émigré intellectuals who have had limited interaction with people inside of country. His call for intervention echoes last year’s call among Europeans, especially the French, to act in Libya, though in this case of Syria, Europe’s position is probably more about asserting its littoral influence than securing economic opportunities in a post-regime environment.

For outside interlocutors assisting the SNC, there is the London-based Henry Jackson Society, which is described by the Guardian as a British group with close ties to American neoconservatives. (The group is named for the hawkish senator from Washington state, who died in 1983.) The American-born communications director of the HJS, Michael Weiss, drafted the “Safe Zone for Syria” document cited by the SNC and advocates of intervention as a blueprint for creating a no-fly zone. The document was prepared with the input of Syrians, according to HJS.

Writing in Slate last June, Weiss assured his audience that “intervention at this moment would be premature, because Syria’s various opposition groups have yet to coalesce into a unified political force worth backing.” But he added that the Syrian opposition constitutes “the most liberal and Western-friendly of the Arab Spring uprisings,” with the clear implication that they deserve U.S. support.

“The more time the world gives Assad, the more he makes a mockery of the ‘responsibility to protect’ doctrine and the more people begging for Western assistance are simply wished the best of luck and left to their grim fate,” he wrote recently in Foreign Affairs,

Other prominent voices in the insular but influential world of neoconservative thought include a team of defense specialists at the hawkish Washington Institute for Near East Policy who recently issued a report concluding, “Intervention in Syria would be a demanding mission carrying significant risks,” while also asserting that “intervention also presents policy opportunities.”

Marwa Daoudy, a former U.N. official and critic of intervention, has noted that idea is supported by a who’s who of Iraq War boosters. One of them is Fouad Ajami, a professor at Stanford, who endorsed NATO airstrikes against Moammar Gadhafi’s forces this past year. Last March, Ajami wrote that “Benghazi would have been Barack Obama’s Srebrenica” if he had not intervened militarily in Libya. “The right thing, at last,” Ajami wrote of NATO’s intervention. “The cavalry arrived in the nick of time.” Ajami is critical of Obama and Hillary Clinton’s allegedly “paralyzing caution” toward Syria.

As Ajami’s comments show, the tragedy of Srebrenica in 1995 – a horrific eruption of ethnic cleansing that killed 8,000 people within sight of a U.N. “safe zone” – animates all sides of the Syria debate. So too has the Rwandan genocide of 1994. Weiss has referenced it in his writings, and at least two prominent Obama officials found President Clinton’s refusal to intervene in that conflict appalling and pushed a reportedly hesitant Pentagon to move quickly.

One of the most influential advocates for intervention in Libya was Samantha Power of the National Security Council, who is only half-jokingly described as Obama’s Paul Wolfowitz by reporter David Rieff. Power is the administration’s most outspoken advocate of “the responsibility to protect” concept, which in its broadest interpretation “holds that when a sovereign state fails to prevent atrocities, foreign governments may intervene to stop them.”

United Nations Ambassador Susan Rice, an NSC staffer during the Clinton administration, was in the interventionist camp in Libya that drew lessons from Rwanda. Time reported that it was Rice who, by virtue of her forceful maneuvering at the U.N., got Secretary of Defense Robert Gates off the fence about committing U.S. air assets over Libya. The National Review suggested that the Pentagon was  “outmaneuvered by three women: Clinton, Power, and … Rice.”

To their number should also be added Anne-Marie Slaughter, who up until the month before the U.S. intervened in Libya was head of the Obama State Department’s in-house “think tank.” Since leaving her post, she has praised the success of the “responsibility to protect” approach in Libya:

For the first time, international law and the great powers of international politics have recognized both the rights of citizens and a specific relationship between the government and its citizens: a relationship of protection. The nature of sovereignty itself is thus changed; legitimate governments are defined not only by their control of a territory and a population but also by how they exercise that control. If they fail in that obligation, the international community has the responsibility to protect those citizens.

Obama, though, did not make his decision solely on humanitarian impulses. Mark Thompson of Time notes how Obama implemented the “responsibility to protect” doctrine: with “a push toward multilateralism and a willingness to hand off command (and responsibility) to others.” Even so, Weekly Standard editor Bill Kristol praised Obama as a “born-again” neoconservative on Libya.

The interventionists continue to push. The SNC has met with Hillary Clinton, and State Department spokesman Mark Toner said on Dec. 28 that the U.S. “would consider other means” in Syria besides sanctions if Assad did not back down. Until at least 2010, President Obama continued the Bush administration’s funding of overseas Syrian dissident groups. And Foreign Policy reports that the administration has convened a National Security Council policy forum with officials from the Treasury and State Departments. Fred C. Hof, a diplomat and academic considered one of the main people linking the U.S. State Department to the Syrian opposition, is a leading member of this small and secretive convocation.

Another factor is Turkey’s role. Any effort to enforce a NATO no-fly zone — either to maintain humanitarian corridors or protected base areas for anti-Assad fighters — would require active cooperation from Turkey. While Turkey denies reports that it has been planning to intervene militarily, the “Free Syria Army” – a loose coalition of anti-Assad fighters – is operating from Turkey, and the Turkish Foreign Ministry is holding meetings with SNC representatives. It is clear that Ankara is taking a hard look at the possibility of a post-Assad Syria. Turkish Prime Minister Recep Tayyip Erdogan told reporters this week that Syria is on the verge of civil war. Since November, Turkish diplomats have been dropping hints that Ankara would consider intervention if the violence gets worse.

Israel is mostly concerned about the influence of Iran. Top Israeli officials have expressed their dismay over the Arab Spring, asserting that it will only empower Islamist groups. But Defense Minister Ehud Barak has also said that Israel views Assad’s overthrow as a matter of when, not if. He did note that military intervention did not seem appropriate at this stage, mainly because in Israel’s view, there is no group yet that Tel Aviv feels it can engage with when Assad is gone.

Syria’s sectarian divisions and central position between Israel and Turkey make it far harder for Washington to reach a consensus on the SNC. At the same time, the centrality of Syria makes it a tempting prize for Washington to gain influence in, if its opposition can somehow be managed. As the Syrian opposition remains fractured and the conflict threatens to spill over into Syria’s neighbors, Burhan Ghalioun’s promises to distance a new Syrian government from Iran and Hezbollah may carry enough weight in Washington to tip the scales in the interventionists’ favor.