So now Eminent Domain means nothing? Even after Kelo v. City of New London?
I don't the government would even after to resort to Eminent Domain. An international border and a certain amount of land on either side is already, by law, considered a federal right of way and they can pretty much do anything they want without as much as even giving the property owner notice. There was a story after 9/11 about some folks on the Canadian border that learned this the hard way, they had owned land right on the border and essentially walked back and forth to Canada at will. They came home from work one day and a big border fence was now going down the middle of their backyard garden.