The German ambassador to North Korea, Thomas Schafer, says he believes North Korean leader Kim Jong-un was forced by hardliners in the military to purge his powerful uncle Jang Song-thaek.This runs contrary to the belief that the young leader ousted Jang to consolidate his own status as the regime's one and only ruler.Speaking at a seminar in Berlin on Tuesday local time, Schafer explained that North Korea is under a collective leadership system and said Jang's purging signals the military's tightened grip on power.According to the German diplomat, the military was threatened by the regime's push to open up the North Korean economy and to strengthen cooperation with China.Jang was a key player in dealing with Beijing.Experts say Jang's dismissal will inevitably deal a huge blow to North Korea-China relations.Jang was known to be in charge of a joint economic zone with Beijing near the Chinese city of Dandong with plans to bring in North Koreans to work in Chinese factories.However, progress has been slow and just before Jang first went missing, Pyongyang announced a new, separate economic zone at Sinuiju without consulting Beijing.With Jang officially gone, other joint business efforts could be for the chop.This, experts say, will add to China's growing frustration with its neighbor's ongoing economic woes and its refusal to give up its nuclear ambitions.But they say Beijing will not let go of Pyongyang for now.As much as the cost of sustaining its isolated neighbor may have increased and the benefits decreased, the potential consequences of cutting North Korea loose are unpalatable to China.Hwang Sung-hee, Arirang News.