Alessio Romenzi A member of the Free Syrian Army holds an AK-47 in Al Qsair. Jan. 27, 2012

All Western interventions in messy civil wars on distant shores seem impossible until they become inevitable. Yet, not even the horrors being visited on an effectively defenseless civilian population by the Syrian regime’s mechanized assault on the rebel-held neighborhood of Baba Amr in the city of Homs look likely to move Western intervention in Syria from the “impossible” column to the “inevitable” one. Hundreds appear to have been killed over the past five days as regime forces have used tanks, rocket fire and helicopter gunships in a brutal effort to reestablish control over neighborhoods that had been under rebel control since late last fall. But while Western publics wince at the spectacle of a hopelessly unfair fight, their governments have no appetite for intervening in a sectarian civil war with no clear end game and rapidly multiplying perils.

Syria’s escalating civil war breaks down on largely sectarian lines, resonating with a regional polarity that has Saudi Arabia and allied Sunni monarchies at one end, and Iran’s Shi’ite theocracy at the other. Regional sectarian divisions are at their most volatile in neighboring Iraq and Lebanon, where sectarian partisans are already actively assisting their kin in Syria, exacerbating the fragility of each country’s domestic political balance.

(PHOTOS: Free Syrian Army Joins Anti-Assad Protests)

So, even if Russia and China had not vetoed U.N. Security Council demands for an end to Syrian President Bashar Assad’s repression, Western powers remain reluctant to repeat the Libya experience in a conflict that may already have more in common with the breakup of Yugoslavia than with the Arab Spring. As brutal and dramatic as the regime’s assault on Baba Amr has been, Homs is unlikely to be Benghazi, where NATO warplanes flew to the rescue at the eleventh hour. Right now, it’s looking more like Grozny, the insurgent Chechen capital flattened by then-Prime Minister Vladimir Putin in the fall of 1999 to stake his nationalist claim to the Russian presidency.

Direct intervention is still largely ruled out by Western—and even Arab and Turkish—policy-makers. But the option of indirect intervention, through arming the rebel forces to even up the fight, is gaining traction in a policy debate fueled by the emotionally intolerable ineffectiveness of options currently being exercised. Sanctions and scolding have not restrained Assad, and Russia and China vetoed the Security Council attempt to demand a halt to the regime’s military campaign against the opposition. Assad may have told the Russians he’s willing to talk about reform with a loyal opposition, but he’s not about to call off the assault on armed opposition groups and the communities in which they operate.

Turkey is taking a lead role in efforts to coordinate a united effort with Western governments to force the issue of getting humanitarian supplies to the besieged Syrian communities. But it remains to be seen how willing to confront Assad the Turks will be if he proves unwilling to allow such assistance. Arming the rebels, however, offers no quick solution to the plight of Homs, or to the wider Syrian conflict. Instead, it’s an acceptance that the war will be protracted and bloody. And it’s on the agenda by default because no other options seem to offer much hope of staying Assad’s hand.

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Marc Lynch, a George Washington University Middle East expert who advised the Obama Administration on the Libyan intervention, urges policy makers to look beyond the “do-something” appeal of sending arms to the opposition and consider the difficult questions it raises. First, Lynch asks, who would be armed? The fighting on the ground is principally being undertaken by the Free Syrian Army (FSA), which he notes “remains something of a fiction, a convenient mailbox for a diverse, unorganized collection of local fighting groups. Those groups have been trying to coordinate more effectively, no doubt, but they remain deeply divided.” This point was also confirmed in the reporting of my colleague, Rania Abouzeid

Nor is the situation much clearer in respect to the political leadership: The exile-based Syrian National Council is being anointed as the representative of the rebellion by a growing number of foreign powers, with Arab League governments considering formal recognition. But the SNC is frequently challenged by activist groups on the ground in Syria, who make no secret of their suspicion of its leadership. Nor does the SNC control the FSA (which doesn’t necessarily control the fighting units on the ground). Creating a cohesive opposition political and military leadership is acknowledged as the immediate priority even by those who advocate arming the rebellion, but that may take some time.

Arms shipments arriving in a fluid rebel political situation become a currency that could exacerbate competition and divisions. And as the rebellion becomes more militarized, the non-violent activists who led many of the early protest actions with a vision of a more democratic, inclusive Syria will become increasingly marginalized. Civil wars tend to put the hard men in charge; just ask the Kosovars. The sectarian character of the fighting on the ground also imperils prospects for stabilizing the situation through an inclusive political settlement. The increasingly dangerous post-Gaddafi power vacuum in Libya gives further pause to those considering the idea of arming loosely organized militias.

(MORE: Reports of Hundreds Killed in Homs, While Diplomats Fiddle at the U.N.)

Then there’s the question of the strategic purpose of arms shipments: Even if they could provide sufficient firepower to prevent rebels from being overrun in towns like Homs, that’s not an end in itself. And it would take a lot more than light infantry weapons to even up the odds on the battlefield. Andrew Exum at the Center for New American Security, who blogs as Abu Muqawama, takes a look at the inventory available to the regime’s forces—some 5,000 tanks, more than 3,000 armored personnel carriers, 3,500 artillery pieces and hundreds of thousands of men under arms—and states the obvious: Absent direct intervention by forces wielding the means to destroy some of that capability, as when NATO aircraft destroyed the Gaddafi forces’ heavy weaponry, it’s hard to imagine the odds being significantly improved by transferring light infantry weapons to the rebels. Doing so, in fact, will raise pressure for heavier direct intervention.

Lynch says that providing enough weaponry to allow a rebel insurgency to survive and weaken the regime’s hold on parts of the country could bring Assad to the negotiating table. But that would mean accepting a protracted war, which all the outside powers are trying to avoid. For Assad, however, if he can’t bludgeon the rebellion out of existence—as the extraordinary resilience of the rebel fighters demonstrates—then a protracted military stalemate that forces Western powers to negotiate with him (what I call his Milosevic option) remains his next best outcome.

“Arming the Syrian opposition is not a cheap and effective substitute for military intervention,” Lynch warns, “and it is not a generally harmless way to ‘do something.’ It does not guarantee either the protection of the Syrian people or the end of the Assad regime. It is more likely to produce a protracted stalemate, increased violence, more regional and international meddling, and eventual calls for direct military intervention.”

(MORE: Syria’s Clashing Armies)

But none of that means it won’t happen. While the U.S. and British governments insist that arming the rebels is not a policy option they’re considering—while not taking any options off the table, said State Department spokesperson Victoria Nuland on Thursday, “we don’t think more arms into Syria is the answer”—they may, as in the case of Libya, simply be called upon to nod and wink (and provide discreet assistance) to the efforts of others. First and foremost among those could be Qatar, although the Saudis can be expected to give generously to a Sunni rebellion against a detested Iran-aligned secularist.

In the climate generated by the relentless stream of video evidence of the brutality being unleashed in Homs, the question in the policy debate may simply become: You got a better idea? In part, that’s because of one key difference between Homs and Grozny: Back in ’99, there was no Twitter, no YouTube, and most cell phones weren’t yet video cameras. The world won’t be allowed to turn away as easily from the horrors of Homs.

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