If the people were just slightly empowered it'd be a civil war with a billion people - the current leaders would be quartered and placed into BBQ pork buns!
Well they had that tune on repeat for about a 150 years on and off up until the final Communist takeover in the 50s. It's just possible that they are still sick enough of war that there would be no enthusiasm for it, no matter how tyrannical the leadership gets.