We unleash the Columbians and half of the Venezuelans against Chavez... we might lose F/A-18 to mechanical failure in support, but I doubt it.
The North Koreans will get crushed in about 2-3 months of bombing. The Ides of March are upon the North Korean government, for sure. We'll lose a few aircraft, but nothing we cant replace. The Chinese will mass on the border, but wont cross. They are as sick of the NK's as everyone else is. Think of it like Mexico and Cuba going to war. Even though Mexico is an "ally" of the US, having it implode might do it some good. Either way, the US can stomp on Mexico or Cuba if need be.
Russia can barely keep a few radical Mooslems at bay, you really think they are going to stick their neck our very far? They have no reason to go to war anywhere for anything. If they rattle their rusty sabre anywhere, it will be vs Ukraine, Belarus, Poland, and the rest of the former Soviet/Warsaw Pact nations over the natural gas supplies and the NATO connections. I doubt much will happen in our lifetime.