I'm guessing back channels are important because it would allow, nations to talk honestly about the situation they are in "off the record",
Say, Castro not really wanting war during the Cuban Missile Crisis. Maybe that's how did JFK knew not to attack. Castro didn't want war? Maybe he was a puppet.
Maybe, Kim Jon Un talking honestly to POTUS. Maybe Kim didn't want war? Maybe he was a puppet?
Maybe Ukraine didn't want war. Maybe the nation was having it's strings pulled. Maybe they were puppets.
Maybe they all just wanted their strings cut. Anyway, just thinking.