China, would not send aid with their armed forces. However, Russia and maybe China would fund them and might supply them with military hardware. Russia's geopolitical goal is to become a regional power and since the United States and NATO are basically the Russian Bloc, it would only make sense to counter the United States in an underhanded way.
Now, I'm not informed on NK's nuclear program, but since it's their first time deal I'd assume that it does suck ass. If this stuff does go down in the form of a war, the majority of the middle east would essentially freeze like in the Cold War.(including Iran and their stuff program) No major conflict because America is a highly emotional nation that overreacts to situations. This makes them very dangerous in conjunction with their Herculean sized industry.
Next, America has the largest navy in history. This is useful when cutting off supplies to the region by sea. I don't think that NK is a threat...