Communist China has long been aware that its ally North Korea is often more trouble than it is worth. Periodically, the North Korean regime does things that have the same strategic insight of a three-year-old’s temper tantrum. Their provocations seem designed purely to get attention without regard for what that attention will be.

One area of particular concern to China has been North Korean ballistic missile tests. These tests not only upset other nations in the region, they also potentially draw American interest to the Western Pacific where China’s goals are best served by staying below the radar. China has even voted on two occasions in recent years to impose sanctions on North Korea… and then turned around and used fig-leaf justifications to ignore those same sanctions.

North Korea may have pushed the envelope a little too far.

A week ago, while Japanese Prime Minister Shinzo Abe was visiting the United States, North Korea decided to launch another ballistic missile. The only reason it did so was to draw attention to itself as two regional opponents were meeting. Then, on February 14, the half-brother of Korean ruler Kim Jong-Un, Kim Jong-Nam, was assassinated in Malaysia. Kim Jong-Nam had at one time been heir apparent but, being as daft as any other member of his family, he managed to embarrass his father and end up in exile. While in exile he has been supported and protected by the Chinese government. And China has retaliated:

China will suspend all imports of coal from North Korea until the end of the year, the Commerce Ministry announced Saturday, in a surprise move that would cut off a major financial lifeline for Pyongyang and significantly tighten the effectiveness of U.N. sanctions.

Coal is North Korea’s largest export item. The ministry said the ban would come into force Sunday and be effective until Dec. 31.

This is non-trivial. Coal accounts for 40% of all North Korea’s exports.

It seems like China is firing a very large and loud warning shot across North Korea’s bow to try to get it to cease and desist in its very unhelpful activities. If that doesn’t work, this coal embargo is a very effective tool for driving a wedge between the ruling oligarchy and the lackwit with a bad haircut who is supposed to be in charge.