How can the North Korean government so successfully deceive the entire population?

They must keep out all foreign media – Internet, books, movies, magazines and videos. Doesn’t anybody get suspicious? Does North Korea send athletes to the Olympics? What would happen if and when they returned?

The stories I hear about refugees crossing the border is always the same – absolute astonishment over the lies that they have been told. If North Koreans knew what life was like across the border in China and South Korea, they would all be out on the streets.

Can’t the West drop leaflets or videos or send radio broadcasts?