However , following the Russian intervention in Syria in September 2015 , Jordan began to withdraw its support for the Southern Front . When Russia entered the conflict , Russia and Jordan " agreed to coordinate military operations in Syria " , according to a statement from Russian Foreign Minister Sergey Lavrov . This entailed Jordan and Russia securing an informal truce in Daraa . Following a series of terrorist attacks in Jordan in 2016 — in Karak , al-Jafr , and al-Rukban camp — Jordan sealed its border with Syria , depriving the Southern Front of arms and other support . The withdrawal of support precipitated infighting between the Southern Front 's 58 constituent groups , with Jaysh al-Islam and MOC-backed al-Rahman Legion clashing in Eastern Ghouta
Karak
2016 Al-Karak attack
Jordanian intervention in the Syrian Civil War