libs are perfectly aware this began as a civil war and fully back the Ukrainian state's ethnic cleansing policies

To me, this demonstrates a lack of understanding, not a total understanding. They just don't know shit about the situation (minor details like the fact that they would consider most of these kids to be Ukranian) but are happy to shout "Russia Bad."

There's a reason you can pry libs away from supporting wars over time -- eventually the facts come out (for example, more and more press admitting that there are Nazis in Ukraine), and some of them will respond to that. They just aren't going to sift through the propaganda on their own.