About any fence

Since you might favor fencing the borders, you could thereafter run the risk of falling calmly asleep only to wake up to see that it was a useless fence; that it could bring on an isolation even more dangerous than any original threath; that you could get caught with the wrong people on the right side or the right people on the wrong side; and that, when all things are said and done, you are never really sure about who are in and who are out. How do you intend to manage these risks?