Answer:
America cannot have a completely open border, for then there will be no "United States of America". A nation is defined by it's borders, and for it to be a sovereign nation, there must be a border, as well as guards to the border. In the case of opening the borders, you are essentially not only taking away the sovereignty of the nation, but also taking away from the very definition of a nation, "a large body of people united by common..., inhabiting a particular
land". Without a border, without protection, without those who want to continue to help the US grow as a nation, America will not survive. In fact, no country will survive, as their benevolence will lead to structural & internal collapse.
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