The Syrian government and a group of self-described “moderate” rebels have agreed to a ceasefire in the area just north of the key city of Homs, allowing for the implementation of the third of four planned safe zones meant to keep combatants separated.

Russian officials have announced that they will send military police to set up this new safe zone, establishing checkpoints to divide the fighters, and observation towers to ensure that neither side enters the newly demilitarized area.

Russia had already done this in the two southernmost safe zones, and neither case has seen substantial incidents of fighting since, leading to hope that the safe zone idea, which was long rejected by many, may finally provide some level of calm, at least in parts of the country.

The fourth and final safe zone will likely be the most difficult, as it is the largest. This northernmost proposed zone cuts deeply into rebel-held Idlib Province, and is intended to separate the coastal Latakia Province from the myriad rebels packed into Idlib.

The Idlib zone would require acquiescence from multiple rebel groups, including al-Qaeda, and its sheer size is likely to make it impossible to implement as currently envisioned, as it would oblige the Islamist rebels to give up key territory.