One idea that I used to want to turn into reality is to have a game where you run a counter insurgency operation. It would be a closecombatlike RTS with realistic mechanics where you need to pacify insurgent areas but there are tons of civilians around and the more heavy handed you are and the more civilian casualties you cause, the more international condemnation you draw until they bring down the hammer and you get sanctioned, bombed and invaded.
I still think it's a neat idea but I have released a few games now and I know the amount of work needed would be way too much, and the game wouldn't be popular enough to make it worth it, so I'm not even trying.
Ignorance truly is bliss.