SYRIA may be the last major domino to fall in the Arab Spring. But war and a tangled power struggle make it difficult to discern how a functioning democracy can rise out of the wreckage of the Assad regime - and if so, at what price to the neighbourhood.
The Saudi, Gulf and Jordanian monarchies, for now at least, have dodged the reform push - in Bahrain through a brutal put-down and in the case of the Saudi regime, by splashing bribes worth billions.
But Bashar al-Assad's days are numbered. The revolt in Syria is perhaps the most powerful in the Arab Spring uprisings in terms of its capacity to rock the region. The stakes for its neighbours cannot be exaggerated.
In a new Cold War-era standoff with Washington and Europe on one side and Moscow and Beijing on the other, the collapse of Syria will make Iran's Shiite leadership more vulnerable in three crucial regional and global fronts: the US-led drive to curb Tehran's nuclear ambitions; its challenge to Israel for the balance of regional power; and its headbutting with Saudi Arabia in the Sunni-Shiite contest unleashed by the US-led invasion of Iraq.
Separately, Assad's demise will create a fourth problem for Iran, by hyping the nationalist aspirations of its northern Kurdish community - estimated to number as many as 8 million, or 10 per cent of the Iranian population. This is a problem Tehran will share with Baghdad, Ankara and whatever new governing entity finally emerges in Damascus.
The area called Kurdistan straddles the borders of these four nations and is home to as many as 35 million Kurds, whose dreams of an autonomous existence have been rekindled by the success of the Kurds in carving out a thriving, self-governed space for themselves in the north of Iraq.
In Syria a decision by Assad's generals to deploy troops normally stationed in the northern Kurdish communities to the front-line defence of the capital, Damascus, and the country's biggest city, Aleppo, has emboldened Syria's 2 million-plus Kurds, who now claim to be ''in control'' of their towns.
Turkey, home to the greatest concentration of Kurds, fears that Syria will become a sanctuary for its outlawed Kurdish separatist movement. In a bid to prevent general Syrian violence spilling over the border and to curb Kurdish excitement, Turkish forces this week moved tanks and other heavy weapons to the border region and a dozen members of the separatist movement PKK were killed in a series of raids.
Splits over which side should be supported in the Syrian conflict is causing such tension in the region it reportedly provoked Washington to intervene last week to defuse a standoff between Iraqi Kurdistan's Peshmerga fighters, who support the Syrian rebels, and forces of the Shiite government in Baghdad, which is siding with Assad's Shiite-aligned Alawite regime and with Tehran.
Similar standoffs are happening in Lebanon. There, a small Alawite community and the Iran-Syria sponsored Hezbollah militia and political movement have thrown their weight behind the beleaguered Assad, provoking violent clashes.
Ironically, it was a greater military role for Syria in Lebanon after the 1989 Taif Agreement that stabilised the country after 15 years of war - but now conflict in Syria is reopening old wounds. Acknowledging the threat of spillover violence to their dysfunctional system of government, all sides in Lebanon have pleaded for calm.
Bahrain remains an ugly mirror image of Syria. In the tiny Gulf state, a minority Sunni regime lords it over a Shiite majority.
Amid all this, a Western chorus is urging greater support for the Syrian rebels - most recently, it includes defeated French president Nicolas Sarkozy, former British defence minister Malcolm Rifkind and the former US presidential candidate, Republican senator John McCain.
Watching it all unfold with increasing anxiety is Israel. Reports that the US and Israel are discussing the possibility of air strikes to destroy Syria's chemical weapons arsenal, and post-collapse planning were the backdrop to a warning this week by a senior Iranian security official, who was quoted on Syrian TV: ''Iran will not allow the axis of resistance, of which it considers Syria to be an essential part, to be broken in any way.''
Apart from developments in Syria and Israel's long-standing push for the US to opt for military strikes against Iran's nuclear facilities, Israel finds itself surrounded by widening uncertainty.
To the north, Hezbollah has tens of thousands of rockets that Israel fears could be unleashed as part of an Iranian or Syrian bid to widen the Syrian conflict - which would be in keeping with the quip from a Syrian security officer who told a foreign visitor: ''My friend, we can burn down the entire region.''
Israel is less certain about its peace treaties with Jordan and Egypt, both of them cornerstones to years of relative peace; just as it is about the will or capacity of new governments in the region to crackdown on anti-Israeli activity.
This war has a way to play before we get to these more thorny regional and international problems. Assad still is well armed and has the backing of Moscow, Beijing and Tehran. Analysts warn the regime is reverting to a ruthless militia-style operation that could provoke a Lebanon-style civil war. One of the most explosive elements of this dire equation is the fate of the regime-aligned Alawite community. Aligned with Shiite Iran and Iraq, they are the targets of intense rebel bitterness. In a sober warning, a report this week by the International Crisis Group said: ''Syria's future largely depends on the Alawites' fate.''
The ICG rationale is that by marginalising the Alawites, the rebels will be planting the seeds of the next conflagration. That, in turn, would exacerbate well-grounded fears among other Syrian minorities, such as the Kurds, Druze, Christians and Ismailis. It concludes: ''If Alawites cannot find their rightful place in it, Syria will face the likely prospect of instability, civil strife and fragmentation.''
Tufts University's Vali Nasr singles out the Sunni-Shiite strand as the one that matters most. In The New York Times last year, he was insightful: ''The war in Iraq first unleashed the destructive potential of their competition for power … The Arab Spring has allowed it to resurface by weakening states that have long kept sectarian divisions in place … Today, Shiites clamour for greater rights in Lebanon, Bahrain and Saudi Arabia, while Sunnis are restless in Iraq and Syria.''
The prospect of Syria and perhaps even neighbouring countries becoming the setting for a real or proxy war between Riyadh and Tehran, Sunnis versus Shiites, has caused some analysts to speculate on a bigger sectarian conflict - possibly from Lebanon, through Iraq, to the Gulf and beyond.
That ICG report observes: ''Seventeen months of bloodshed and destruction have not been enough for either the regime or its opposition to put forth a proposal that does not involve eradication of the other.''
Therein we can find a meaning for the line from a former Obama official quoted in The Guardian: ''Syria won't implode - it will explode.''
Paul McGeough is Fairfax chief correspondent.