whatever one thinks of rojava, they should have seen an american withdrawal coming. lessons for the revolution; it's cliched, but it's the blunt truth. it's not like they had much of a choice, but they should have known from the start that they were eventually going to need to defend themselves.
there's not a contradiction in supporting some kind of kurdish self-determination inside syria, and supporting an american withdrawal - for the same reason that there's not a contradiction in supporting the withdrawal, and leaving the remaining fighting up to the russians.
the bottom line is that i don't think it's reasonable to call for american imperialism to protect anarchists in a fictional kurdistan. it's a nice idea; it's not very rooted in reality.