The last part of the Syrian conflict will be the diplomatic level. The U.S. invested in the Geneva process which has led nowhere while Russia invested in the Astana process which has resulted in a series of de-escalation agreements. By doing so Russia was able to cut the United States out of negotiations on the future of Syria by working only with Iran and Turkey. This means that the U.S. role in eastern Syria is conducted in a vacuum without a diplomatic track or a track that combines diplomacy and military affairs. Ideally the United States has to settle on a policy that combines its anti-ISIS program with its policy on Iran with a new mission in eastern Syria.

Seth J. Frantzman is a Jerusalem-based journalist who holds a PhD from the Hebrew University of Jerusalem. He is the executive director of the Middle East Center for Reporting and Analysis and a writing fellow at Middle East Forum. Follow him on Twitter at @sfrantzman.