There's method to Kim Jong-Un’s reported madness (in US corporate media). This is the thesis argued by the author that attempts to give a rational perspective from North Korea's point of view, and I think he is quite convincing.
...the strategy of the Pyongyang is working: on the one hand, they are developing a nuclear weapon to deter external enemies; on the other, they are obligating the PRC to adopt a particularly hostile attitude towards South Korea’s deployment of THAAD. In this sense, the numerous economic actions of Beijing towards Seoul can be explained as a response to the deployment of the THAAD batteries. China is the main economic partner of South Korea, and this trade and tourism limitation is quite damaging to South Korea’s economy.My only criticism is this statement referring to the THAD missiles the US has installed in South Korea: "As repeatedly explained, it is useless against North Korean rockets...." I am quite well-read (def.), but I often skip over technical details of weapons. Thus I was offended by this statement and the fact that he didn't bother with furnishing a link to support it. Here is such a link from a South Korean source.