Maybe if we started hanging their bodies on the border fences, the ones that would follow will get the message.
My dad used to tell a story of the Turkish Army in South Korea doing that with a thief. This would have been in the early 1960s.
Apparently, their base didn’t have nearly the problem with thievery, that the U.S. Army base did.
Our allies, the Brits, used to display the heads of criminals on London Bridge, the main entry route from the South.