Russia and Turkey negotiated a ceasefire deal for Syria last December. The ceasefire more or less held albeit with significant violations.
Meeting in Kazakhstan the two powers along with Iran, have now negotiated to prolong and strenghten the ceasefire.
However, just like all previous Russian-proposed ceasefires the deal explicitly exludes the Syrian al-Qaeda affiliate Jabhat Fateh al-Sham (former Jabhat al-Nusra).
This means that every rebel group which accepts the terms of the ceasefire regime in effect vows to stand by idly as Syrians, Russians and Americans tear Jabhat Fateh al-Sham to pieces.
JFS is naturally deathly afraid of being isolated and singled out in this way. Moreover it is understandably upset since it has so far acted as the shock unit of the rebellion. While not quite the largest outfit in rebel ranks it has led the charge in numerous battles.
Thus its understandable reaction: JFS has attacked a number of smaller rebel outfits aiming to forcefully incorporate them into its ranks or at least capture their weapons and territory.
They are joined by at least one other group, the Nour al-Din al-Zenki of the child beheading fame, who used to be counted among “moderate rebels” and received US weaponry and western political and moral support.
What is more, sources close to the rebels report JFS has even carried out suicide attacks against them.
Multiple civilian casualties reported & many prisoners taken.
— Charles Lister (@Charles_Lister) January 24, 2017
This has in fact been a modus operandi of JFS (previously Jabhat al-Nusra) for years. They have always policed the Islamist rebellion, shutting down outfits which they saw as unreliable and stripping them of their weapons.
They particularly leaned on FSA groups after US first bombed them in September 2014 after which US bombing of al-Qaeda promptly stopped.
This time however JFS’ attacks on smaller groups caused the only still more powerful group, Ahrar al-Sham, to issue an ultimatum against it. Ahrar is part of the ceasefire deal and the two appear close to blows now. A clash between the two would truly signal a rebel ‘civil war’.
On the other hand Ahrar al-Sham is very close to JFS in ideological terms and has shared the battefield with it many times. Just a last month it seriously considered a merger with the JFS, precisely in order to shield it from such isolation.
If the two fight it might very well be that the contest is decided by defections rather than by battlefield casualties.
In any case if the Russian plan for the ceasefire was to hand over a poison apple to the rebellion that would tear it asunder it has worked wonderfully.
Perhaps this is the reason why Russians have appeared previously to favor ceasefires almost at any cost.
Even if rebel infighting dies down, however, the ceasefire deal still allows for them to be easily subdued in a piecemal fashion. If JFS is taken out then the military position of the rest of the (majority Salafist) rebellion is that much weaker and they’re in a worse position to seek concessions.