In the face of the larger narrative being built in this thread, I'll go against the grain a little:
We told the Kurds that we are embedded and nothing will happen to them as a result. They made defensive And offensive changes due to that agreement. They were in fact a large portion of the body count against isis. Implied and factually, I think we all agree that our presence is the only reason that Russia and Turkey weren't already in the area wrecking the Kurds.
We can say all day that the Kurds aren't "allies" and try to relabel them partners or whatever. But the reality is that we set the stage for them to get overrun with ease. Turkey creating a "safe zone" is 100% propaganda. Turkey looks to divide Kurdish populations for their own domestic political issues. 300,000+ Kurds that are not fighters in anyway are currently displaced since the offensive and Turkey is not at all and acting a ceasefire.
Maybe you think it's great that Turkey is doing this and we are pulling back. Some seem to think so for lots of different reasons (us leaving or even a realpolitik move to bog down Syria with Turkey invading) But at least call it what it is. It is not Turkey creating a Syrian safe zone to repatriate refugees.
Another unpopular opinion...
Syrian oil fields are legitimate military considerations. The biggest problem is the Helter skelter US policy in Syria, But if we are going to be there performing military action this is a legitimate part of that. It is initially legitimate even under peacekeeping and ISIS removal.
The big question is what is the US policy on Assad? Is now very poorly defined.
If we are returning to a demand of removal, then the oil fields should be prevented from Assad and ISIS. We also owe a UN mandate for Assad removal if that is the case. Which will never due to Russia and China.
If that is not our demand, which has seemed the case since Trump got elected, then the oilfields should be released into the new Kurdish/Syrian alliance that came about as a block against the Turkish invasion we incited. But then we still started a new and enhanced the civil war.
Tldr: no matter what we screwed over the Kurds and we shouldn't have.