It is often said that, lately, the Kremlin has been successfully punching above Russia’s economic weight in the global arena. Surprisingly, Russia has positioned itself as a reliable partner, an actor that would never betray its allies or clients. Not publicly and unambiguously, at least.
A false impression? Sure, but impressions matter. To the superficial observer, the US has just betrayed its Kurdish allies (or junior partners, or vassals, or clients). The US withdrawal might have been the least disastrous outcome of lengthy negotiations, or even the only option short of going to war with Turkey, but it surely looks like a brazen betrayal from the outside.
Which is poor strategy, to say the least and to put it mildly.