It’s no secret the situation in Syria is a clusterfuck, and the latest action in Eastern Ghouta, in which airstrikes have killed hundreds of the roughly 400,000 trapped residents, is fresh evidence. Below, we detail the rebel groups in the area, along with their allies and geopolitical links. (with help from DW and SBS News.)

Jaysh al-Islam (Army of Islam) – Along with Faylaq al-Rahman, one of the two biggest rebel groups left in the area. Various estimates on the size of their forces range from several to 15,000 fighters. The group’s main objective is to replace the Assad government with one based on Sharia law, a goal shared with Hay’at Tahrir al-Sham (HTS), and Harakat Ahrar al-Sham al-Islamiyya. There are rumors the group is backed by Saudi Arabia, which it denies.

Faylaq al-Rahman (al-Rahman Legion) – The second largest rebel group in the region, Faylaq al-Rahman is directly opposed to Jaysh al-Islam and allied with Hay-at Tahrir al-Sham (which, to reiterate, has goals similar to those of Jaysh al-Islam). The group is backed by Qatar – feuding with Saudi Arabia for months, by the way – and has ties to the Free Syrian Army. There are no reliable estimates on the number of Faylaq al-Rahman fighters in the region, although it’s likely there are significantly fewer than there are Jaysh al-Islam fighters. Faylaq al-Rahman claims they’re not trying to establish an Islamic government, although they are attempting to overthrow Assad.

Hay'at Tahrir al-Sham (HTS) – Salafist militant group previously known as al-Nusra Front with ties to al Qaeda that is attempting to violently overthrow Assad to implement an ultraconservative Islamic government. It’s estimated there are several hundred HTS fighters in Eastern Ghouta.

Harakat Nour al-Din al-Zenki movement – Sunni Islamist group from Aleppo whose list of achievements include beheading a 15-year-old boy on camera. Previously received financial backing from the United States.

Harakat Ahrar al-Sham al-Islamiyya – Another group seeking the establishment of an Islamic state in Syria run through Sharia law. Believed to have tens of thousands of fighters (although not in the Eastern Ghouta region), as well as heavy military hardware such as tanks and mobile artillery. They’re directly opposed to HTS, and have received financial backing from Saudi Arabia, Qatar, and Turkey.