Who else should the enemy be? the concept of being attacked by the japanese and the germans have worn pretty thin over the years, and there's not exactly much else to shoot at, is there?
The french? Just mute the cries of "we surrender" and it'll be like a rail shooter.
The norwegian? (yeah, using them as an example out of national pride. Or something.) Last time the norwegians went to a war -if that was what it was, they never really decided if it was a corporate takeover, a war, a military action, or an act of peace negotiations- most of the soldiers were sent home due to lead poisoning. And that's not slang for getting shot, either. Good old, honest to ned flanders, chew on your pencil lead poisoning.
Maybe we should give new zealanders a chance to get shot in a virtual war game? Do they even have an army?
And the list goes on. Looks like we're stuck with russia for now; they might not be the best choice, but they're better than risking bad publicity by using some minority group from ooga-boogaland. And they have voice actors who manage to sound passable; that's a big plus over german, where everyone either speaks american, or sound like they learned german from an american wartime sitcom.