Unfortunately your option 4 is the wishful thinking the starry-eyed idealists in our foreign service and media have been whispering among themselves for 20 year

Unfortunately your option 4 is the wishful thinking the starry-eyed idealists in our foreign service and media have been whispering among themselves for 20 years. The Chinese coms like the regime in the North very much, thank you. It keeps regional rivals Japan and South Korea off guard, and keeps the U.S. tied-up. The Kim dynasty could not even exist without the backing of the PRC. We let slip the window of opportunity to exert pressure to change the situation in the early 90s. Instead we sent nuclear technology, oil, and food, which Kim tells his people is tribute from the U.S.