I don't think there will ever be another world war on the scale of the previous two.
The world has become so interconnected economically and communications-wise that more sway goes into foreign policy than just bat-shit crazy governments deciding to go to war.
Also the general population has become too humanistic. We won't get anything on the scale of Soviet Russia accumulating millions of troops and sending them to their deaths. Most countries' populations (at least the ones who would be able to wage a large-scare war) wouldn't allow it.
The only way I ever see a world war-type conflict occurring would be if the economic system completely and utterly collapses, with nations being cut off from food, water and natural resources. But in that case, the conflict would be more along the lines of general anarchy rather than an organized, conventional world war.
Tag (Courtesy of Fkusumot) "If I'm posting in this thread then it's probally a spam thread."
