Honestly i'd be happy with Something minor, yet tedious. That left unattended may grow to something that you should deal with. but not be forced to deal with.
little in game notifications.
Rebels near the city of "X" attacked a checkpoint, killing 5-10 soldiers.
Rebels detonated an explosive at a fuel deput. 100 fuel was destroyed.
Rebels took hostages at the bank. (it doesnt take money until you deal with it.) (a max units sent would be 20, at most you risk losing 10 when retaking it.)
If you ignore them for too long, they start getting more ballsy.
Anti-gov forces have taken control of "X" improvement with "Y" "soldiers" and "z" tanks. Dealing with them in a manner similar to regular war.
Anti-gov forces destroyed a "X" mine. (or similar cheap improvement.)
If Rebel or anti-gov forces are active in your nation, Enemy Spy operations get additional options.
Supply rebels/A-G forces with Anti-air/Anti tank missiles for 5 days. (allowing them to destroy a small amount of each unit every day. around 3-5%) (allows them to destroy a few Air/tank units if you use them to deal with the rebels. )
train rebels/A-G forces. So they do increased damage against checkpoints. again only for 5 days, as the good ones get killed off..
Little things like that. Maybe so i wont get disappointed when my notification is nothing more than some !@#$ retiring.