In reality, I totally think that America will not go to war with China and North Korea, and Iran. All three wars would totally result the US to issue a military draft. Bad news for USA, especially when taking on China, resulting in numerous casulties. This leaves the door open for al Qaeda to strike in US, and probably Russia.
If this were to happen, China would be under heavy military strikes, because the American dominace of Asia has been almost surrounding China. Just take a look that are now American puppets: India, Taiwan, Japan, South Korea, and the Pacific Islands. Total bombarages in the Eastern part of China, and where the majority of the population of China and military forces are stationed.
While this is all happening, the war with NK would result in a nuclear strike by NK. This will result in every country with nuclear arms to turn to nuclear weapons, especially Iran and Russia. More bad news for USA. As more and more nukes result, the end of the world is increasing.
If 200 nukes were to bomb the world under a 5 year period, Earth would be totally back into when the metour hit earth in the Periodic Era and will wipe us out.