With most of the suburbs of Damascus recaptured by the Syrian government by February 2018, there remained a significant swathe of the countryside near the capital city captured by fundamentalist rebels from the mainstream ones in 2012 that had been under siege by pro-government forces since 2013. The rebels used to shell the capital daily and tried to infiltrate it many times.
Syrian forces began bombarding and shelling the area in early February after Russian-brokered peace talks failed, killing 200 by 8 February, according to the Syrian Observatory for Human Rights. They again started bombarding it on 18 February, and did so for eight consecutive days before beginning the ground offensive.
The main rebel faction in the area was Jaysh al-Islam, based in Douma (with an estimated 10,000–15,000 fighters in the region in early 2018). The second largest was Faylaq al-Rahman, an official affiliate of the Free Syrian Army (FSA), controlling much of central and western parts of Ghouta, including the Jobar and Ain Terma districts. In addition, Ahrar al-Sham (based in Harasta) and Tahrir al-Sham (HTS – controlling smaller districts such as Arbin,
Hawsh Al-Ash'ari and
Bait Naim, with an estimated strength in the area of 250-500 in February 2018) had a far smaller presence.