Aye, railguns could be used to put a shell deep into the African desert into a space the size of a small house. Very precise, could be very powerful, but I think few of the former superpowers could manage it. The European, Asian, and American countries would be the primary people there- they'd be working the ruins. Meanwhile, places like Africa, South America, perhaps Canada, and maybe smaller island nations, such as the Philipines, might be relatively untouched by the war. They'd be the new America to everyone else's now-third-world.

I am reserving the Southern American countries, btw.

Oh, and yes, that would be cool, except my nation is pretty much on the tip of the bottom of the world. South Africa (Madagascar included) is only really close to the rest of Africa, or Saudi-Arabia.

Speaking of which, the Middle East is relatively unclaimed, so that would be a good place to get. Being always warmongering, they'd be untouched by the war because they're already warring, and people wouldn't have time for them... or people would focus on them because of oil and stuff. Either way, the Middle East is still unclaimed and could be very prosperous.