WWIII will not happen until October 24th, 2013.
The world will be thrown into chaos and former allies will be enemies, with few ally groups remaining.
Everyone will start throwing missles at each other and shooting and stuff until May 14, 2014, at which Iran attacks the Americas, the UK, Russia, Africa and Canada with a bioweapon.
The bacteria in it is loaded with junk DNA that will accidentaly get mutated and merged with the main DNA that turns it into a parasitic creature that eats most of your brain and takes over your body, however it enters the body in a bacterial form.
The people who are naturaly immune will survive while the rest of the world becomes infected. This will mark the end of WWIII and the beginning of the 12-year period known as the Outbreak which will eventualy lead to the Omega period and the rise of humanity from the ashes of chaos.
I know this because I made it up :D