Amidst all the tensions on the Korean peninsula there is another worry that nobody has mentioned. The North Korean leader may be rational, as some analysts have stated, and may realise that starting a war would mean the end of his regime. However, he is obviously a narcissist and probably a sociopath as well. He is also intelligent. As the sanctions begin to bite and reduce the money flow to his regime he may well consider the possibility of selling nukes and missiles to terrorist organisations. That way he gets money and can start a nuclear horror without his regime immediately being blamed.
This possibility is a very scary one and if the Trump government in Washington has realised it, that could be behind their apparent keenness for the military option. It must persuade China of the imminent danger.