Japan succeeded with he closure all through the Tokugawa Bakufu. It was only opened up by the outside with the force of cannons. They would have gone along with it for as long as they could have. A better example would be China closing itself by destroying all of its blue water ships. Poland has found a way to stop all immagration coming into the country: they have authorized the boarder guards to shoot to kill. That’s how they are defending the boarders.