I wish so much that a war against Iran happens. Then we'll see Iran-China-North Korea-Russia against USA-South Korea-Israel. Of course first side will win, and USA will finally fall and with it the New Jewish World Order !
North Korea is the annoying little brother of China. I don't know if they would support the illegal government of North Korea during a war. USSR times are long past and China has more cost than benefit with NK. It's more probable the Chinese would ensure Korea remains divided. China doesn't want a powerful Korea, they have enough competition with South Korea and Japan already.
A war like this could happen, but I do not agree with your statement. Mexico will win, because the others will bomb each others to death.