Having said all that, here's my timeline for a possible DPRK-ROK war (in the event that the DPRK leadership, feeling threatened internally by their apparent irrelevance, decide to flex their muscles for the home crowd a bit, and it's optimistic, though it does show the possibilities of yet another world war):
Setting: Korean Peninsula, Sea of Japan, East China Sea, and the Yellow Sea
Time: 2003 June
2003.06.11: After an impassioned plea by the new and embattled ROK president Roh Moo-hyun at an emergency meeting of the UN (he was flown to Busan two days earlier, and left the country for New York on the 10th), the UK, Germany, France, Italy, Turkey, Poland, Spain, Mexico, Brazil, South Africa, and Norway commit troops.
2003.06.16: Fierce fighting on sea continues between the USN/ROKN and the DPRK navy, which is expected to tilt overwhelmingly in the allies' favor once the US aircraft carriers arrive in the area. Hu Jintao meets the DPRK envoy and, reminded of the long history between China and Korea, as well as some recent (clandestine) agreements, reluctantly agrees to aid the DPRK (but not initially militarily), much to the chagrin of the rest of the world. Enthusiasm around the world for a quick end to the new Korean conflict fades even faster as an increasingly senile Fidel Castro also meets the DPRK envoy to Cuba and pledges support. Vietnam commits troops to the DPRK, which causes the Philippines and Indonesia to mobilize their fleets and air wings in order to intercept any Vietnamese troop transports.
To be continued...
The Germans aren't going to commit troops to a real war zone like that. At least not without a huge fight in bundestag over it, and likely not even then.
What's in it for the Chinese? That would cause them huge economic problems. And the Vietnamese? Why?