Located in eastern Syria, Deir ez-Zor lies alongside the strategic border with Iraq. Part of Islamic State (IS) territory, the region is the focus of attention from forces loyal to the regime of Syrian President Bashar al-Assad and the US-backed, Kurdish-dominated Syrian Democratic Forces (SDF). With IS’ downfall, control over the region will require the collaboration of the tribes dominating the Deir ez-Zor landscape, a process complicated by local dynamics and possible intertribal strife.

Since September, SDF forces and pro-regime forces have been increasingly fighting to expand their zones of influence. According to a report by the Institute for the Study of War (ISW) issued Sept. 27, Russia installed a bridge over the Euphrates River, allowing pro-regime forces to cross the river after conducting overnight airstrikes against SDF positions near Deir ez-Zor city. The strikes came one day after the SDF-affiliated Deir ez-Zor Military Council asserted that its fighters would resist efforts by pro-regime forces to cross the Euphrates River in eastern Syria, according to the ISW.

Despite the fact that US-backed coalition forces appear to be focusing on fighting IS, the expansion of the SDF is a sign that the United States intends to maintain a zone of influence in eastern Syria. “The US calculates that it does not only intend to liberate the region from IS, but also prevent the group’s comeback as it was previously the case in Iraq,” Bassam Barabandi, who recently co-authored a paper on Deir ez-Zor tribes in October for the Center for a New American Security (CNAS), told Al-Monitor. US ambitions could be seen as a direct threat to Russia’s Iranian ally, which is seeking to expand its foothold in the region neighboring Iraq to ensure a continuous corridor from Tehran to Beirut via Damascus.

In this dangerous game, regional and international players will have to regain the trust of Deir ez-Zor tribes that constitute the region’s main social and political fabric. According to a report by the Justice for Life Organization (JFLO), there are several prominent tribal confederations, the most important being the Egaidat confederation, which includes Bu Kamal, Bu Kamil and several subtribal affiliations. The Baggara is another important confederation, explained Eyad Kharaba, a Deir ez-Zor activist who spoke to Al-Monitor. According to the JFLO, the latter confederation incluldes Abeed, Sultan and Abed.