Striclty theoretically speaking if humanity lasted forever there could never mathematically be an end to war. This is because with enough time war will crop up again due to the right circumstances coming around again. Humanity is not likely to last forever so you could say there was an end to war if the sun blew up during a long period of peace or another galactic disaster wiped us out in one swift blow. However, I think if we had warning we would have riots and quite possibly war.
Bookmarks