President Trump's precipitous withdrawal from Syria was a blotch-stained end to ten years of US policy incoherence. Our strategery, such as it is, was a congeries of mutually-exclusive goals and conflicting aspirations sitting heavily on a shoddy framework of criminal ignorance, venal Do-Something-ism, and cynical, fatalistic diplomatic puffery and posturing.
We wanted to topple Assad, while also protecting the minorities he was protecting, while also defeating the jihadis who were trying to topple him, while keeping the Russians and Iranians out (who were already in), while being buddies with both the Kurds (our fighting partners) and Turkey (a NATO ally), despite the fact they have a hateful, murderous feud going back centuries.
Anyway, here is a good article on the subject. If you're interested, please read it and tell us what you think. Despite the title, the authors do not like President Trump and make no defense of his actions.
What Trump Actually Gets Right About Syria