As I learned International Relations, nations have "interests". Such interests drive both internal and external national policies. While relationships may occasionally matter a great deal between heads of state, interests usually trump them when push comes to shove. Time passes; situations evolve, relationships change, old interests atrophy, new interests develop. Things ebb and flow. European colonialism dramatically dissipated after the Second World War. The "American Century" seems to have passed. China's current "Belt and Road" initiatives are far beyond anything Mao Zedong might have imagined. I suspect Danes might find current US and Chinese interests in Greenland somewhat bemusing, mostly perplexing, and possibly alarming.
If it helps to understand how I think East and Southeast Asians view each other and China, it might help to compare how Scandinavians occasionally view each other and Russia; the regular frictions which occur among them exist without hostility. Russian investment is welcome, Russian meddling is not.
But back to your original point about North Korea's MIRV missiles, I still think it is just another piece of evidence that not much has changed. North Korea remains a dangerous place and the suffering of it's population continues unabated.