This is a rather long article with many links to document his arguments. Nevertheless, if you can spare the time, it will offer you important information, and one that I will supplement by another Kuwaiti independent journalist, that contributes to a comprehensive picture of the terribly complicated, game-changing and potentially explosive nature of the present situation in this area.
Because I don't like to be dependent on one source of information, I am supplying you with another article by Elijah J. Magnier, an independent Kuwaiti journalist, entitled "A US buffer zone in north-eastern Syria and a land-Bridge from Tehran to Beirut" which corroborates much of Bernhard's post and offers more information on this volatile area. I have provided the following maps: one furnished by Magnier that I've enlarged, and have provided another so that you can clearly see what both posts refer to.
I am providing you with one more link which will confirm Bernhard's claim that the US military advised the Syrian Kurds to add "democratic" to their name. See this general's remarks at 25:10m into his talk at the Aspen Institute in July of this year. This is an illustration of how attuned US leaders are to framing issues to hide their illegal and criminal activities behind nice sounding words.
To disguise its cooperation with the Kurdish terrorists, the U.S. renamed the group into the "Syrian Democratic Forces" (SDF). Some Arab fighters from east Syrian tribes were added to it. These are mostly former foot-soldiers of ISIS who changed sides when the U.S. offered better pay. Other fighters were pressed into service. The people of the Syrian-Arab city Manbij, which is occupied by the YPG and U.S. forces, protested when the YPG started to violently conscript its youth.However, I think the Syrian Kurds are more complicated than he describes them here. They do have some factions among them that have appealed to US leftists. I think that they were fighting for survival from ISIS forces (the US played both sides in relation to this terrorist army) when they teamed up with the US military and allowed the latter to construct bases on territory which they controlled in northeast Syria. But I think that now their continuing collaboration with US forces is a very serious mistake.