Shafaq News/ The Jerusalem Post said that pro-Turkish and pro-Iranian groups prefer to see the tribes fighting the SDF and see US influence reduced in Syria.
The Iranians back the Syrian regime, and the regime and Iran have their own proxies west of the Euphrates River in Syria. Meanwhile, Ankara backs the remnants of the Syrian rebels, groups that it has armed and used to fight against the SDF in the past.
According to JP, what unites Turkey and Iran is their opposition to the US role in Syria. This means that "as tribes chafe under the SDF rule in areas east of the Euphrates, a number of groups may be seeking to fuel this conflict. These groups may be present in Deir Ezzor, but also in areas Ankara occupies near Manbij."
The article highlighted the importance of the middle Euphrates River Valley area or MERV. "Historically, tribes here sought a degree of autonomy in their own affairs. In the 1980s, some people in the area felt more connection to Iraq and Saddam's regime than to the Assad regime."
"After the US invasion of Iraq, this valley was a conduit for fighters and weapons going to Iraq to back the insurgency. After 2013, ISIS entered the area and massacred some tribes and recruited others. Later, the US-backed SDF was able to defeat ISIS on one side of the Euphrates River, while Iranian-backed militias came to control the western side."
The Jerusalem Post revealed that Iran began to move weapons up the valley from Iraq to help Hezbollah in Lebanon. Turkey, which has backed Sunni Arab elements in Syria and tends to spread influence among the tribes, also seeks a role here. "This creates a difficult situation for the US-backed SDF and US forces in the region."