If when Scotland becomes independent, where in England will the MOD store it's weapons of mass destruction? Currently many of them are stored under the mountains near Loch Long?
Personally I think that one of the big things that will come into play is fresh water. As global warming continues, increasing population density in the Midlands and south of England, where will you get water from? We have lots and lots here. Short term maybe not a problem, but long term
As to the RAF patrolling our skys, last time I checked part of our tax goes towards funding the armed forces, the RAF is part of that.