I had the privilege in 1979 of traveling in Eastern Europe and crossing the border in a rural area between DDR (East Germany) and BRD (West Germany) with my US

I had the privilege in 1979 of traveling in Eastern Europe and crossing the border in a rural area between DDR (East Germany) and BRD (West Germany) with my US passport. The East's border was two 3m (10ft) fences topped with razor wire, with a 10m (30ft) gap of ploughed land between them. I assume the ploughed land was a minefield, but I didn't ask. There were towers with fixed machine guns and searchlights positioned closely enough together to allow the soldiers in them to monitor everything. Inside the border was a 5km exclusion zone. The West German boder? A small guard post, with a passport control officer dressed in blue jeans, and a sign saying Wilkommen in BRD. (Welcome to the German Federal Republic). 5k inside the western border was a sign in English saying "no US military personnel beyond this point." (At that time the post-WWII Allied occupation forces were still in place.) What does a border look like that prevents the passage of determined people? It looks like that, or like the Wire of Death. It's doggone ugly.