I felt that withdrawing from Syria was a huge mistake, because of both the continuing global threat of ISIS and the fact that Iran's substantial influence would undoubtedly grow. I had argued to Pompeo and Mattis as far back as June that we should end our piecemeal policy in Syria, looking at one province or area at a time (e.g., Manbij, Idlib, the southwest exclusion zone, etc.) and focus on the big picture. With most of the ISIS territorial caliphate gone (although the ISIS threat itself was far from eliminated) the big picture was stopping Iran. Now, however, if the US abandoned the Kurds, they would either have to ally with Assad against Turkey, which the Kurds rightly considered the greater threat (thereby enhancing Assad, Iran's proxy), or fight on alone, facing almost certain defeat, caught in the vise between Assad and Erdogan.