You do know we have come VERY VERY close to world war 3 in the past 20 years on various occasions right ?

That had nothing to do with scientists actually... sure there were weapons, but it was mainly a direct result of the cold war that was (is?) going on... You can't blame "scientists" as a group for politicians that nearly screwed up big time or at least trying their best to spread fear into people into thinking the big bad Soviet Union is the enemy (wasn't true, the Soviet Union did not want to start a World War III ). After all, it was the US government that sort of wanted to start a war... It's a good thing they listened to some people who said that the collapse of the Soviet Union was only a 'matter of time' (that wasn't quite true either, but still... as insane as it is, there were a few times where the USA seriously thought about dropping the bomb.).

You do know a new world war could potentially kill EVERY single human in the planet right ?

Which... as insane as it sounds, is something 'you' guys usually see as something potentially good. You know... the end of days, judgment day, the apocalypse and so on.

"Now tell me how religion can beat that."

Actually that's not difficult at all. Give an example of 1 war that did NOT start because of religion. :P