The First world war and the second world war was about 25 years apart, It has been almost 70 years since the end of the second world war, I'd say we are overdue for number 3. Who do you think will start number 3 ?

Personally I think both Israel and Iran are willing to attack each other, they just need a catalyst.(Although if they fight it might not end up as a world war unless they drag their allies into the fight and even then I doubt it)