This report charts some of the major developments in northeastern Syria from the December 2018 withdrawal announcement up until the start of Operation Peace Spring on 9 October 2019. It describes and notes the significance of the bitter dispute between Ankara and Washington over a proposed "safe zone," analyses how the Syrian Democratic Forces (SDF) have sought to navigate the crisis and gauges the strength of the so‑called Islamic State (IS) in Syria. Providing this context enables this report to selectively incorporate more limited analysis on the latest and most pertinent developments in northeastern Syria at the time of this writing.

Following President Trump’s decision to withdraw troops from northern Syria, Belfer Center experts discussed the impact on America, our allies and adversaries, and the region.