Suriya al Kubra!!
The road connecting Homs and Damascus is critical for Syrian President Bashar al-Assad's survival, but is likely to come under concurrent attack from the Islamic State AND Jabhat al-Nusra.
Crucially, Homs province connects Damascus province to the coastal mountains, which constitute the Alawite heartland. Maintaining that supply line open is critical for the ability of Assad's Alawite-dominated government to govern from Damascus. Moreover, the presence of a significant Alawite community in Homs is a further factor that would cause the Syrian government to give priority to relieving jihadist pressure around the city. Additionally, the prolonged closure of the Damascus-Homs road would likely destabilise Assad's hold on power for several reasons, even if, as is likely, the jihadists were unable to keep the road closed and Assad had to concentrate forces to keep it open at the expense of other sectors.
First, this would lead the Iranians to question the viability of Assad and his security forces as the best representatives of their interests in the Sunni-Shia war.
Second, it would lead the Alawites to question whether Assad is still the best option to protect their interests. That might well make the Assad's removal in a military coup more likely.
An offensive by Jabhat al-Nusra and the Islamic State, probably working independently and aimed at severing communications between Homs and Damascus, is likely in the coming weeks. The Syrian government is likely to dedicate significant resources to defeating any such offensive. However, given how overstretched the Syrian forces are, this may well force it to pull back critical resources from other areas such as Aleppo. The Syrian government in Aleppo has already been significantly weakened, and a withdrawal of some forces from there to Homs may well pave the way for an insurgent takeover by the city, most likely by Jabhat al-Nusra and Ahrar al-Sham.
This kind of major defeat in either Aleppo or Homs would be likely to destabilise Assad's hold on power, as his domestic Alawite supporters and his Iranian sponsors might well decide that his removal is necessary to bring different elements of the Sunni population hostile to Jabhat al-Nusra and the Islamic State to the negotiating table. Even Assad's removal would, however, be unlikely to end the war in Syria, as many militant groups would not accept a government which included any of Assad's current ruling elite. Moreover, even in the event of a peace agreement, the large numbers of militias in the country would take years to disarm, and infighting between them would also continue.
Pic - "A “core interest” after all “that children are not having barrel bombs dropped on them, that massive displacements aren’t taking place.”