Who wants to guess at how much a 2,000 mile "fence" would cost and how long it would take to build?
I've done the math. Five years and $100Trillion. Then $20T every year to maintain.
Five years?
I think you're being generous.
This is not a cheesy chain link fence they're going to put up in the desert. It would have to be more like a substantial wall with concrete abutments and barbed wire and the like.
So let's say they could do a hundred yards a day (the length of a football field). No, let's give them 200 yards a day. That's 600 feet, but they're very industrious, hard working people. In nine days, they can complete one mile. At that rate, the full 2,000 miles will take somewhere in the neighborhood of 50 years.