The Washington Post reports: Radical fighters staged a strategic retreat from a key Syrian town on the Turkish border Friday amid growing tensions with rival rebel factions that threaten to erupt in a new war.

The retreat from Azaz of the Islamic State of Iraq and Syria ended a five-month reign of terror by the renegade al-Qaeda faction, which has used its position in the town to control access to Turkey and compromise supply routes for more moderate rebels.

The withdrawal could signal a new phase in the intra-rebel fighting that has pitted more moderate factions against extremists across northern Syria in the past two months, undermining the wider battle against forces loyal to President Bashar ­al-Assad.

The exit came a day ahead of a deadline issued by Jabhat ­al-Nusra, the official al-Qaeda affiliate in Syria, for ISIS to cease confronting rival rebels or face a new war. Commanders speculated that the ISIS fighters, who have resisted previous attempts at mediation, chose to pull out from Azaz to reinforce strongholds elsewhere in preparation for further conflict. [Continue reading…]