North Korea is an isolated and secretive country. Its leader, Kim Jong-un, took power in 2011 after the death of his father, Kim Jong-il. Since then, he has doggedly pursued the development of a nuclear bomb. The United States has long been considered the deterrent to other nations developing nuclear weapons. But that hasn't stopped Kim. In 2017, North Korea declared they had developed a missile capable of reaching North America. Now mounting tensions between the two countries' leaders is bringing the world to the brink of potential war.

From the Curio channel: News in Review.