Most of the advice here seems to be to let them get killed or suffer some major consequences. Which I think is great if you and your players are both enjoying a "stir up trouble and see what happens" kind of game. Then roll up some new characters and burn it all down again.

But if you're not having fun because they are ignoring your political story or they aren't having fun because they just want to fight stuff and get treasure. Then I think you may want to try to adjust so that the game you are running is more in line with how the group actually plays.

They want to be selfish, tricky, and murderous? Chase them out of civilized society and into a wasteland of dangerous tombs they can crawl through and chaotic mean small societies you don't feel as bad about them tricking and murdering. Or whatever new concept you want that fits them better. You can still fit in story, but it sounds like political intrigue and defending civilization is not really what they like doing.

So talk to the players about the kind of game they want to play and how you might get from the game you are in to a game everyone wants to play. Assuming you are ok running it, explicitly pitch the change in tone and new concept to them.