Why The Race To Oust ISIS From Deir Ez-Zor In Syria May Present New Dangers

Syrian government troops and allied militias are locked in a race against rebels backed by the United States for control of Deir ez-Zor, an oil-rich province that will give whoever governs it greater influence in the country's wider civil war.

Government soldiers and supporting militias have now crossed the Euphrates River, which had served as an informal dividing line between them and the U.S.-backed Syrian Democratic Forces (SDF) as they waged separate offensives against ISIS in the area.

The move has brought regime troops within miles of the U.S.-backed forces and puts two sides on a potential collision path that reveals the deep complexities and unresolved questions over who will rule in a post-ISIS Syria, pitting the