North Korea needs China for survival: Why does Beijing need Pyongyang?

Chinese President Xi Jinping arrived in Pyongyang for his first visit in seven years, aiming to boost ties with North Korea, a reclusive nuclear-armed state. The China-North Korea relationship dates back to the Korean War (1950-1953), when China helped North Korea fend off UN forces. A 1961 Treaty of Friendship obliges China to intervene militarily if North Korea is attacked. However, China has opposed North Korea's nuclear tests, straining relations at times.