Walls can be used both ways, depending on which way the guards are facing. The difference is who (now and in the future) will be in charge of the wall.
They can only be used “the other way” if the American people are disarmed first.
Ain’t gonna happen.
Nobody is going to work as a border guard keeping Americans “in” because they will be plinking targets to out past 1,000 yards. And all the way up the chain of command to the POTUS and every .gov stooge in between.
Everybody knows that Switzerland has not been invaded in many centuries. It also has not had a tyrant. No job security in being a tyrant or a tyrant’s stooge in a country with uncountable numbers of scoped deer rifles that can blow holes in 200# mammals out past 500 yards.