Is that because gamers are a jingoistic bunch who wouldn't want to shoot their own side? Or is it just that the British and Americans mostly won their wars, and games tend to cast the player as part of the winning side?
Maybe, but Counter Strike is the type of game that have two sides, and was very popular. Well, that depends on definition of winning, and on the mindset of the game creators. The gaming today is dead experience, mostly because of poorly scripted scenarios that offer rigid events with book-like pass trough.
There was a rather good strategy game I picked up long ago called 'Central Intelligence' in which your job is to organise a revolution on behalf of the CIA in some banana republic. Set up safe houses, establish contacts with sympathisers in the media and among the student radicals, organise a leaflet campaign, put up propaganda posters, raid the quarry and steal explosives, send a letter bomb to the chief of police...
Sounds like standard CIA type of plot ( Iraq, Bulgaria, Serbia? ). It form your brief description sounds like a good game, I hope that it has open ended scenarios, unlike most of other games.
There's got to be a market for this. 'Freedom Fighter' - play as Lenin, Collins, Mao, de Gaulle, Guevara, Khomeini!
There might be, but in real life there is another variable, that tends to become constant, and that is foreign/international corporate business...
Overthrow the corrupt puppet government of the oppressors! Establish liberty and justice for the common people!
... and the replacement government becomes even more corrupted, according to my experience, and part with justice and common people, looks just like a bad joke.
Intimidate and beat up collaborators! Execute informers! Blow up police stations!
It just cant be done without THAT in real life, and why not in the game.
Yes that is most intriguing and absolutely heretical idea and could make an interested game. Anyway, such game should have two sides, the hero side and the antihero side ( look for Dungeon Keeper ) where evil is good.