Create an impregnable shelter which covers the U.S. and all her territory. This shelter must have walls AND ceilings.

The United States hasnt been invaded for over two hundred years. How about we keep it that way. Make the whole country into a fortress. We may have doors that shift open and closed, but the only thing we would use them for would be so we could fire thermonuclear warheads at unsuspecting communists. Other than that, nothing gets in or out of the barrier. In essence, my proposal is a dome if that helps you visualize. We could make everything we need and be totally self-reliant. Thus, trade with dirty commies would be unnecessary. I know what you are thinking: wont a dome block connections with our satellites? The solution is that we make more satellites and have them hover inside the dome with us. This way we can still use long-range communication. Lets put aside our differences and do this!