Gosh, mikkin, that stirred up the pond, didn't it!
Germany has started the conquest of Europe with an army of faceless bureaucrats - much cheaper than tanks... but that won't make a World war.
There are nuclear weapons in Pakistan, ex-Soviet states and soon to be Iran, perhaps. These states have religious extremists who could get their hands on them, and might start something, but hardly a World war.
No, I think that global warming and / or the next Ice Age will do for us.
Glorious criticism invited.