North Korea launches ballistic missile across northern Japan, falls into sea

[Anomalocaris]

The only thing the Chinese can do to stop him would be to invade and occupy his country.

Don't you think tighter trade sanctions -- say, not buying any DPRK coal, or not selling it any oil -- would if not stop the regime's shittery at least reduce its brinksmanship?

Keep in mind Kim's nukes are not just his insurance policy against an American led regime change.  It is also a insurance against a Chinese led regime change. America's track record of invading and deposing despots who do not sing our tune must be truly frightening to him. But at the same time he must also be worried that china is holding him up as a shield against American encroachment with one hand, and with the other hand scheming to replace him with a more pliant puppet. He is not going to go easy on his nuclear program just because it is the Chinese, and not the Americans, who are really squeezing him.

But for China's perspective, China will also never tighten the sanction to the point where North Korean economy will collapse. There are two main reasons

1. This is related to his nukes being an insurance against china as much as against the US.  For Kim the death of his regime means his own death because his family killed far too many people over almost 70 years, and far too many victims and family of victims would be looking for revenge if he loses the protection of his security services.  He knows this, and china knows he knows this, and there is no telling what a nuclear armed Kim regime will do in its death throes.  If Chinese sanction is the final straw that broke the back of his regime, he may well lob a few nukes into china as his final revenge before he is caught and killed.

2. China doesn't want American forces on its borders.  It doesn't want to engage in a dangerous race with American and South Korean forces to secure North Korea, with all the attendant possibiliites of two sides ending up shooting at each other. So it wants North Korea to survive.

So long as Kim regime has enough trade from china to survive, plus some amount to spare because china probably doesn't want to,cut it too close lest they misjudge and strangle North Korean economy by accident, he has room to follow his real priority, which is to make it very clear he can hurt the US and will not be cowered from doing so if the US threaten his regime.  The subtext is also he can hurt the Chinese and will not be cowered from doing so.  

America is his avowed enemy, china is his much resented benefactor.  Saber rattling against the US fits his narrative, and threatening china does not.   but the subtext is clear.  If North Korea can hit Guam. It can hit every major Chinese city.