Chinese actors remain vital for North Korea's drive for nuclear weapons:
A team of UN technical experts and sanctions investigators issued a report in early 2017 agreeing with South Korean allegations that North Korea was not only obtaining key components and manufacturing equipment via China but also prohibited raw materials and cooperation from Chinese banks and companies to pay suppliers and hide these activities from outside scrutiny. The Chinese government still denies knowledge of these activities but the latest evidence was so detailed and well documented that China did admit it must be acted on.
(China has had a role in keeping Iran's American-made F-14s in the air, too.)
Maybe offering trade concessions to China as the carrot to the threat to attack North Korea will work.
But I think we'd get China's more enthusiastic help if we make North Korea a problem China cares about:
So if China won't solve America's (and Japan's and South Korea's) North Korea problem because the problem isn't bad enough from China's point of view, perhaps we need to make a problem that China does care about.
We could quietly let it be known that America will be willing to help South Korea and Japan to each match North Korean nuclear weapons warhead for warhead to deter North Korea.
I suspect that the possibility that Japan and South Korea will have nuclear arms (and if they go nuclear, Vietnam and Taiwan and perhaps others will see a green light--or at least an opportunity to get lost in the outrage directed at Japan and South Korea--to go nuclear) would be important enough to get China interested in solving a nuclear proliferation problem among potential foes of China.
China doesn't think it is so bad to have North Korea pointing nukes at America, Japan, and South Korea?
Well maybe America won't think it is so bad to also have Japan, South Korea, and Taiwan pointing nukes at China.
