The Tlas defection: A tipping point for Syria?
For more than a year, Syrians have waited for a big defection.
For months, only conscripts and mid-level officers peeled away from the government of President Bashar al-Assad. Late last year, Mustafa al-Sheikh became one of the first generals to jump ship, eventually taking charge of the Free Syrian Army's military council.
Turkey's foreign minister has put the tally at "around 20 generals and maybe 100 high-ranking officers, colonels". But in tight-knit dictatorships, rank means little. None of these, including the dramatic escape of a pilot to Jordan, have been game-changers.
The latest defection, however, is a big deal: Manaf Tlas.
Why Tlas matters
Gen Tlas commanded the 10th Brigade of the Republican Guard, an elite force led by Bashar al-Assad's brother, Maher. The Guard, which has six brigades, also oversees the army's Fourth Division, instrumental in the past year's military offensives.
Although his departure has hardly crippled the Republican Guard, it is the strength or weakness of these units that will affect the government far more than defections from the regular army.
Moreover, Manaf Tlas is more than just a general. His father is Mustafa Tlas, who served as defence minister for 30 years and was a confidant of Hafez al-Assad, the president's father and predecessor.
Both Manaf and his father have been key Sunni powerbrokers in a regime that is dominated by the Alawite minority sect to which the Assad family belongs. Tlas junior helped Bashar take over his father's role, when succession was far from certain.
The government has long relied on such cross-sectarian alliances to anchor itself. For example, the Vice-President, Farouk al-Sharaa, touted as a potential transitional leader, is also Sunni. So too are the interior minister and the head of the General Security Directorate.
The government's ties to the urban Sunni trading classes, particularly in Damascus and Aleppo, have also helped its survival - although these are under real strain.
Gen Tlas's defection is therefore significant for two reasons. First, although his absence will not in itself be a major blow, the signal it sends to other non-Alawite elites could be important.
Other generals may not have Gen Tlas's wealth and connections; some might still be tempted to leave while they can.
And with the loss of this Sunni veneer, those Sunni factions hitherto sitting on the fence - like many business people - may also be persuaded to tilt to the opposition. Even if a cascade of defections is unlikely, this could herald a shift in the balance of power.
Joshua Landis, the director of Middle East studies at the University of Oklahoma, has argued that Gen Tlas was tasked with quelling rebellion in the Damascus suburbs of Harasta and Douma last year.
The general reportedly negotiated an agreement with the rebels to have each side step back, but was overruled by Alawite figures and was squeezed out of office and denied further promotion.
According to an anonymous Syrian source quoted by AFP, Gen Tlas then "gave up his military uniform and opted for civilian clothing [and] set up residence in Damascus, where he let his beard and hair grow long".
If disagreement over strategy has reached the inner sanctum, it suggests that there may be other disaffected regime members.
This will force decision-making into an ever-smaller circle, perhaps leaving the regime more estranged from even its elite officers and less amenable to any compromise.
Although the experience of Libya's uprising is cautionary, suggesting that cohesive security forces can survive even high-level political defections, there comes a point at which the government's base is just too narrow.
So whose side is Gen Tlas now on? Some question whether he has in fact defected - ie actively joined the opposition - or simply deserted in order to protect his wealth.
One problem is that, even if he had been passing on information while in office, as is rumoured, he would not be privy to up-to-date information, like the location of key units, owing to his marginalisation.
Additionally, while some see him as a potentially bridging figure, his prominent role by President Assad's side would make him extremely divisive among the opposition.
Gen Tlas's defection comes at a sensitive moment. The flow of weapons and ammunition to the rebels - funded by Qatar and Saudi Arabia, and abetted by Turkey and the United States - began to take effect over the beginning of the summer, with the regime now under unprecedented military pressure.
Kofi Annan, despite his ostensibly "successful" trip to Damascus this week, is altogether irrelevant.
If the Tlas defection is a one-off, and Russian financial support continues, it is possible the government will stay resilient. And if it sheds its Sunni allies, this could even push fearful minorities further into the arms of a government that promises to protect them.
Ultimately, though, the defection has probably increased the probability of the regime collapsing from within. As one French diplomat noted to Reuters: "We are now hearing things from within political and military circles in Russia that are surprising us and that we were not hearing before."
The implication is that Russia and Iran could attempt a controlled implosion, by working to replace President Assad with a favoured Sunni successor.
This has been dubbed the "Yemen option", in reference to the way in which Saudi Arabia and the United States eased out President Ali Abdullah Saleh this year. Alternatively, such a successor could emerge independently and try to cut a deal with some rebel groups.
The advanced stage of the rebellion means that either one of these paths would be messy, because large portions of the opposition would not necessarily give up the fight.
What is clear is that, with Gen Tlas's departure, the Syrian government's ever-narrowing base of support leaves it increasingly prone to a collapse that, when it comes, could be both sudden and unpredictable.