So, we don't rebuild N.O. We leave it as a wasteland. We keep the bases.
Now, how are you going to keep the area from being condemned?
I'm starting to realize you MUST be trolling. What kind of durn fool question is that? Bulldoze. Dynamite. I don't care. All that's needed to secure the border (which is an issue you made up) is to maintain a base there. Or within striking distance of there, at least.