Bob, the charge cluster technology is promising, but seems likely to be years from realization.
The article below by former Ambassador Joseph DeThomas, points out that the U.S. accepts nuclear arsenals / deterrence situations with all the other current nuclear powers. If Trump and Kim can cool off, stop threatening each other, a new (obviously uneasy) standoff could be reached. Trump has zero diplomatic skill; we can only hope that Congress and other countries will talk some sense into him.
http://www.38north.org/2017/09/jdethomas092517/
North Korea 'seems' crazy with their public statements. But many acknowledge that this is a tactic to appear strong and imposing, despite the truth of their desperate economic reality. Their leadership just wants what any other country does: autonomy and longevity. Our regular war games conducted in their vicinity and the past Korean War history, clearly contributes to their monstrous fear and self-preservation-at-any-cost.
William