Crimes Against Humanity: North Korea

This is a very disturbing account of what is happening in North Korea. (Link to Der Spiegel)  If the United Nations is the guardian of the peoples of the world, why aren't they doing anything about 'the mass starvation' in North Korea? Do North Korean lives have less value than human life in Africa? Or is the world helping Africa because those military governments do not possess the ability to launch nuclear weapons on invading/occupying troops? How can the world stand by and let hundreds or thousands of North Koreans die so easily?