This game is set in the "near future," yes? Then it's totally Alaska. The state splinters off from the U.S. and uses its dog sleds to overcome the entire U.S. military. And because Alaska can see Russia, taking over Asia was (somehow) a breeze. And the Iditarod? Really just one big reconnaissance mission. All of which was funded through saved up loans and past funding stored under a bunch of mattresses. Wait, why does this now sounds more entertaining...
Jokes aside, I can see how Japan would want to lessen what could be perceived as "flagrantly anti-North Korean propaganda!" After all, look at the country we're dealing with here. Personally, I don't see a "Country of the North" or whatever they want to call it as much of a distraction.
I would take that more seriously than North Korea, so count me in the group that would find China more believable of an adversary.