There is a huge difference between a country building a wall to keep its people in than a country building a wall to keep the people of other countries out who wish to enter illegally.
JMO, a militarized wall, is a militarized wall, is a militarized wall.
Again JMO, building a wall will not solve the problems as they didn't solve them behind the iron curtain.
"Mr. Gorbachev, tear down this wall", Ronald Reagan, Berlin, 1987