We have heard repeatedly from Lakhdar Brahimi, the UN's Special Envoy to Syria, that there is no military solution to its civil war. Brahimi would know, for he helped broker an end to Lebanon's civil war in the late 1980s. The US and Russia now appear to agree with him. So we know what needs to happen in Syria, what we don't know is just how to make it happen.
Bashar al-Assad's regime is gaining ground militarily and holding its own in the propaganda war being played out in the international media. In his standoff with the West over the use of chemical weapons against civilians in Damascus, Assad exposed deep divisions in the US-UK camp concerning its commitment to military intervention in Syria. Whoever threw down the gauntlet by conducting those attacks took a major risk and most commentators suspect that Assad is guilty of this war crime.
By stalling US military action, the Russians bought Assad some time and he has committed to engage in a decommissioning process overseen by the UN. In terms of the international legitimacy this political process will bestow upon the Assad regime, this brazen tactic appears to have paid dividends. However, identifying, locating, securing and destroying Syria's arsenal of chemical weapons will be a most unenviable task. We should recall here that it took the IRA a decade to destroy its guns and semtex during an at times-farcical decommissioning process in Northern Ireland. And they still haven't entirely gone away you know.
The US-Russian diplomatic channel could eventually unlock other doors in Geneva. From this political process, a narrow window of opportunity through which negotiations over how the Syrian conflict could be brought to an end may eventually open. This is not likely but it is certainly possible. Thus Western leaders should now consider constructing a political process that seeks to bring about a new constitutional dispensation in Syria. Proposing the negotiation and implementation of power-sharing arrangements could become a viable policy option.
Using the old Lebanese maxim of 'no victor, no vanquished', a future Syrian government might include elements of the ruling Assad regime and some of those groups challenging it. At present, this idea will almost certainly be dismissed by the warring factions of Syria. None of them want to share power. But we should remember that it was exactly this method of conflict regulation that was proposed in the early years of the political violence that tore apart Lebanon and Northern Ireland in the 1970s and Bosnia in the 1990s. In all three cases there was not enough domestic and international support for the proposed power-sharing arrangements to succeed, yet in all three cases the conflict was ended through the establishment or reestablishment of power-sharing arrangements.
This solution is probably the least unattractive long-term development that could realistically be expected to occur in Syria over the next five to ten years. It would involve compromise - a great deal of compromise - but it might just prevent the worst of the horrors that await Syria should the state collapse and divide, events which would have extremely negative repercussions for the Middle East.
The idea of implementing power-sharing is fraught with difficulties and it will be dismissed by the Syrian National Council and manipulated by the Assad regime. It would also institutionalise a grim Syrian reality - the deep ethnic and religious divisions that are presently destroying the country. Much like its neighbours - Israel, Lebanon and Iraq - Syria is a deeply divided society comprised of ancient ethnicised communities who do not really want to live together.
For this idea to become a plausible policy option the US and its European allies must make a concerted effort to convince China, Russia and Iran that a prolonged civil war in Syria or its partition will damage their interests in the Middle East. Iran has significant interests in Syria, as does Russia, and a power sharing arrangement will not work without their blessing and positive input. So this option entails further backtracking on the part of the US and constructive diplomacy and compromise from Russia and Iran. Any power-sharing arrangement will require a major international commitment to Syria by its sponsors, for it is a country with no history or culture of democratic pluralism.
It would be far better for the West to raise this idea before the Syrian civil war worsens. Imposing power-sharing on a post-Assad Syria which is controlled by different militia factions that are sponsored by regional rivals would leave the country in much the same chaos as Iraq today or Lebanon in the 1980s. If this option is pursued, then some form of military intervention in Syria would ultimately be necessary. Ideally, this would take the form of a UN international peace-keeping force that had the backing of Russia and China on the UN Security Council.
Before dismissing this idea as too difficult or too unrealistic we should consider the alternatives to it. The Assad regime still believes it can win by crushing the rebels in Damascus, Hama, Homs and Allepo. These cities provide access to Lebanon and the coastal Alawite stronghold of Latakia. These are the parts of the state that the regime is fighting for, but it has a long way to go in consolidating its hegemonic rule there. The road to a regime victory is a long bloody civil war.
The disparate Syrian rebel forces and international jihadis, buoyed by some future Western military strikes and armed with the equipment needed to defeat a regular army and air force, may bring about regime collapse. This is an unlikely scenario and it is not something that any of the permanent members of the UN Security Council favour given the political vacuum and sectarian chaos that would ensue.
The civil war could worsen, the state could collapse and Syria could experience de facto partition (which happened in Lebanon during the 1980s). This is one of the reasons why the US and UK governments blinked first when a military confrontation with Assad seemed imminent. Exactly where President Obama's 'red line' lies remains a rather grey area.
Yet for the Assad regime, partition is probably the least worst outcome to the conflict should it fail to win it. The humanitarian consequences of partition would be catastrophic and not just for Syrians. Lebanon and Jordan are already under great strain, and Israel is nervous. The chances of state collapse sparking a regional war are very high.
Internationally, the conflict over Syria is not just about Syria. It is about the projection of Iranian power in the Middle East. And as the Syrians continue fighting, Western clocks tick to the tune of Obama's other red line - the one concerning Iran's future nuclear capabilities. Yet a significant realignment in international relations concerning Syria has occurred in recent weeks, so perhaps now is the time to begin thinking about this third way.
Professor Michael Kerr is director of the centre for the study of divided society at King's College London, and a renowned author who has written extensively about Syria and Lebanon. Click here for more about him and his work.