The only credible argument that I have heard against the withdrawal from Syria is that we would be leaving the Kurds to the tender mercies of the genocidal Islamist regime in Turkey.
But we have no realistic plan for the Kurds except staying there endlessly. Nor has our policy even been to support an independent Kurdish state. When the Iraqi Shiite regime rolled in and went after the Kurds, we said nothing.
That said, the image of the Turkish defense minister promising to massacre Kurds from the Qatari capital, is ugly.
The question is what if anything we could or should do about it. Staying in Syria endlessly is not a serious option. Applying pressure on Turkey is. The UN is useless in that regard.
If Turkey resumes massacring Kurds, there should be a move to expel it from NATO. That will clean up NATO if Turkey goes ahead and restraint it if it chooses not to.