I was just reading about the Kovakistan
campaign (some swearing and drug references .. in fact, have a general content warning) where the players are trying to organise an uprising against US occupation, using mechanics of Secrecy, Public Support, War Weariness (on the part of "US Inc.") and their Bonds, based on the Delta Green ruleset. I don't know that it's a complete sub-system for guerrilla theory yet, but it sounds promising. Violence is certainly on the cards, but head-on confrontation is just not going to work.
edit: Now I have Abba running through my head. An adversary that can't be defeated by combat power: the terrible earworm. This post has been edited by uncle_jimbo on Nov 14 2018, 06:32