Like it or not, this is what i'd do.
Pick a city with bad insurgency problems, well i'd drop flyers and tell the citizens to fight the insurgents, if it was not under control in 2 weeks, your city will be leveled.
2 weeks go by, if the problem persist, drop flyers and tell them all to leave the city, it will be flattened tomorrow at high noon. The next day , i'd flatten the city.
on the flyer would also be, if you leave to go to a new city, we will be watching, insurgents allowed to begin fighting there, we warn you we will flatten that city also.
I'd let them know that its in their hands now, they have way more a majority than the insurgents, tell them its time for them to fight for their freedom. If you allow 1% to control you, we will continue to flatten cities until you are all living in the middle of the desert. It is your choice.
The clock is ticking, take control of your own country now or simply sit back and watch every city be flattened one by one.
GO!