World War III isn't going to happen any time soon, it's not worth worrying about. There are flashpoints for potential major regional wars, but not a world war.Ever since WW2, nobody has bet their country's future on the war saying conventional. Proxy wars, sure. Bit the big one? You want to be really, really sure that the enemy has invested massive amounts of time and effort on weapons they won't use when it's time to.
- Europe could decide to get properly involved in Ukraine, but the most it will likely do is restore Ukraine's territorial integrity to 2014 (not necessarily including Crimea), with that border a very hard, red line it will not cross. Russia might bluster and threaten and moan, but won't fire nukes over it.
- There's potential for conflict in the Middle East, but there are no parties involved with anything like the will and power to get it beyond the Middle East.
- There's a potential Chinese invasion of Taiwan which the USA and other allies join in to defend, but it's never going to go beyond the Far East Pacific rim. China simply does not have that sort of power projection.
I don't really get this fascination people have with dreaming up World War III scenarios. It perhaps made sense in the Cold War, but the world has moved on.