His name is "marx_mentat" and he's from Hexbear, so I think "Russian propaganda" is an obvious answer. If you believe (or pretend to believe) the Russian claim that Ukraine is run by Nazis then western support for Ukraine is trivially spun as support for Nazis.

That’s what’s funny about the incident … whatever you want to think about claims from far leftists or tankies that there is actually a problematic facism presence in Ukraine … this happens where we can only ask “how in the world” while the tankies or whatever are just like “yep told you” and we’ve got pikachu face.