I made a WWII version of risk in highschool for a project.
It was more like castle risk. Different counties got different "powers"
US = nuke = kill all but 1 army on a given country
Russia = winter storm = if anyone attacks you on next two turns, you get +1 on your defense dice and they get -1 on each of their attack dice.
Britian = naval invasion = take as many armies from 2 coutries boardering an ocean and use them to attack any other coastal nation.
Germany = Blitzkreig (sp?) = +1 on all your attack rolls for that turn
Japan = air strike = roll a die and take away that many armies from any coutry on the board (leaving at least 1 behind)
Italy = reenforcements (poor italy) = at the beggining of your turn, turn in your card and roll a die, place that many armies in your territories as you feel fit
I didn't do a very good job balancing the powers each country had, but the game looked pretty good considering I did it in 1 night 🙂