Ask HN: How would solve in-company disputes?

I work at a place where disputes between departments have reached the point I've never seen before: managers forbidding employees to talk to other teams.

Maybe I'm very unlucky, but all the jobs I've so far, with companies ranging from 50 to 10000+ employees, have always had at least 2 departments that actively sabotaged one another.

Is it ever a solvable situation? Imagine you are a person of influence/power in a company like this. How would you go about dealing with this stuff?