Actions of the United States and its constantly changing position cause serious concern among main players in Syria. An already complicated situation gets even more complicated, current situation becomes even more unstable, resembling kaleidoscope with constantly changing patterns. In this situation, it's extremely difficult to predict your own actions, much less someone else's.
Recent visit of American delegation to Ankara, which was generally unfortunate for Washington, only strengthened suspicions that President Donald Trump's statement about withdrawal of troops from Syria wasn't made at the right time. Or he just came up with some kind of unusual combination that will turn all forces in this country against each other.
First version, which in no way contradicts the second one, is supported by the fact that national security advisor John Bolton, while he was in Ankara, didn't hide the fact that he was trying to reach agreement on keeping Kurdish troops supported by the US safe. Bolton even said that American troops wouldn't be withdrawn until necessary guarantees will be obtained. But instead of receiving guarantees, he was criticized by Recep Tayyip Erdogan, who called accusations against his state, fighting against Kurds, a slander.
Such reaction was also caused by the fact that Washington is not paying attention to Ankara's dissatisfaction with US military bases, located in northeastern Syria. Turkish military repeatedly expressed interest in obtaining these bases. Ankara also wants Americans, which are supposed to leave Syria, to take all weapons that they have provided to Kurdish forces with them. It seems that this wish won't be fulfilled - if Americans are concerned about safety of Kurds, they won't take their weapons away, especially since it may turn out to be a difficult process.
American side also doesn't understan another part of the "Turkish scenario", according to which Ankara wants to create "protectorate" over the north-eastern regions of Syria, rich with oil. It seems that they can't accept that someone other than them would control production of hydrocarbons. On the other hand, the “Turkish scenario” is opposed by Arab countries, headed by Saudi Arabia, which has traditionally been an ally of the United States in controversial multilateral disputes. There's also Damascus itself, which wants to keep its oil and believes that it can regain control over its territories. In this case, so-called internal opponents of Bashar al-Assad have similar position - they believe that natural resources belong to Syria. There's also question about capabilities of Turkey itself - after all, control over oil areas requires mobilization of serious forces and resources.
In short, current situation is getting more and more complicated.
Second version (that Washington wants to turn all remaining players in Syria against each other) is supported by the fact that American side took specific steps to ensure safety of its allies, including Kurds, by transferring control over Manbij region in Turkish border area to Russian military police units. Unprecedented transfer of large territory certainly leads to conflict of interests - Turkish side also wanted to take over this area. What happened in the end?
Experts note that Kurdish defense units were under protection of Russia, which, of course, is good for both Kurds and their American allies. Now Americans have freed themselves from this mission, which initially damaged its relations with Turkey, another member of NATO.
Secondly, if there's no conflict between Washington and Ankara regarding Kurdish troops, it may lead to potential conflict between Turkey and Russia, which is now responsible for safety of Kurdish forces. Rapid rapprochement between Moscow and Ankara puzzled the United States.
Thirdly, after entering the zone of America's responsibility, it seems that Russia has increased its own significance in the "Syrian scenario." But on the other hand, it seems that it is becoming even more bogged down in the Syrian conflict, which naturally increases costs and resources needed to maintain stability and support the Assad regime.