I made the mistake of balking at some particularly unhinged Ukraine/Russia rhetoric offline yesterday and got called a vatnik, a tankie, a Russia lover and I was even suspected of being pro-Israel and apparently a nazbol Aimee Therese follower or something
I'm not even invested in this shit, I just find the insane saber-rattling and warmongering unsettling 
When someone tells you Putler's going to invade Estonia, Poland and Finland for Lebensraum next if he's not stopped in Ukraine, just nod your head solemnly
Liberals love to talk down to others, and hate being talked down to. If you can shape your argument such that they can feel some bit of smugness you can reel them in. It works especially well for intellectual liberals if you appeal to their intelligence.
Just pretend to agree with them and put words in their mouth. "Yeah, I can't believe that deranged trumpists think {thing that the libs are trying to advocate for}, you're so right that {position you want the lib to hold}."
This is what all my successes in this boil down to