Here is a little known history about the Korean war - the withdraw of Chinese troops from North Korea in 1958. This can help us understand the delicate situation today between US, China, and NK. In 1956, after Stalin's death, Kruschev led a campaign within the Soviet Communist Party against "cult of personality," mainly to remove Stalin's influence. This campaign echoed throughout the communist world, including NK. The NK Communist Party had several factions. The pro-China faction were people who were in China during WWII (they were in fact members of Chinese Communist Party) and returned to Korea after Japanese surrender. The pro-Soviet faction were people trained in the Soviet Union, the South Korean faction were those who fled from the South. The Southern faction was already purged by that time. The pro-China faction started a campaign against Kim's cult of personality, in response to what Kruschev was doing in Soviet Union. Because of their WWII history and the help of the Chinese army, the pro-China faction were mostly army officers, and presented biggest threat to Kim's power. Kim ruthlessly crushed the pro-China faction. Many of these leaders fled to China, including the party secretary of Pingyang, the political commissars of several armies, and the ambassador to Moscow. Kim sent his men to Beijing demanding the return of these people. After negotiation between three sides, China, Soviet Union, and Kim, the agreement was that these people were allowed to stay in China. In exchange, China had to withdraw all its troops from NK by 1958. The relationship between China and NK has never been good after that. The curious thing today is that all the players, including US, China and NK want the others to believe that China can influence NK. For China the benefit of that is obvious. For NK, its bargaining position would be much weaker if everyone knows that China doesn't support it. The only fool that is being played here is the US.