North Korea and China are not really that close of an ally anymore. When China entered the Korean war on the North Korean's side, one must understand the situation that China was in. China became a true communist nation in 1949. The Korean war followed directly afterwards. With Mao in control the Chinese were basically obliged to help the North Koreans. Nowadays China started the 6 nation talks etc. I don't see why CHina wouldn't want Korrea to be united. As FF said, South Koreans are now required to lelarn Chinese in their schools, this just shows their good relations.