Democracy or self-interest?
The US is promoting its foreign policy interests in the Syrian conflict: namely, the removal of the Syrian President - Bashar al-Assad, who is not pleasing to them, elected by the people, which will lead, at least, to the dismemberment of Syria with the ensuing consequences for the weakening of Iran. Well, a nice bonus will be – unlimited access to the Syrian oil fields.
Based on these goals, the US continues to support the Kurdish forces, as their desire to create a Kurdish independent state in Syria coincides with American interests. At the same time, the United States takes into account the interests of Turkey, just as Turkey is sufficiently dependent on the United States in the financial, economic and military-political spheres as a member of NATO.
The Syrian government has long tried to negotiate with the leadership of the Kurdish armed groups on their integration in any form into the ranks of the Syrian government army.
Negotiations on this topic intensified after the start of the military operation of the Turkish army to create a so-called "security zone" in areas controlled by Kurdish forces.
It should also be noted that the Kurdish armed groups are not a single military structure, subject to a single command and strictly carrying out its orders. At the same time, some Kurdish units joined the Syrian army. However, at present, it is unlikely to expect the integration of all Kurdish forces or their majority in the Syrian government army, as a significant part of their military and political command has links with the United States, receives some assistance from them, and hopes for their support.
Moreover, at this point, the vicious circle closed. The Syrian territory, despite the "Loud" statements of the parties to the conflict, remains the main cause of disagreement. The key that opens the gates to the wealth of the Middle East.