The other day I read this thought:

"It has been said that the First World War was the chemists' war, because mustard gas and chlorine were employed for the first time, and that the Second World War was the physicists' war, because the atom bomb was detonated. Similarly, it has been argued that the Third World War would be the mathematicians' war, because mathematicians will have control over the next great weapon of war--information."

Two questions came to mind:

(1) I've always heard that WWII was largely decided by the success (or failure) of encryption and cryptology, particularly in relation to the UBoats. Any war historians out there care to offer his or her take on this?

(2) What criteria must be met for a war to be considered a *world war? Is there a quarum of participating countries that must be met?