I suppose the cobalt angle is a particularly unhinged possibility, but it would absolutely guarantee the end of the NK regime. The opinion of the entire world would swing. So I rather doubt it.

The more bluster out of NK, the more internal turmoil that makes it necessary. That's my wager.

But it's not NK that is an immediate threat to the Western world broadly, and I'm rather puzzled at the amount of click-bait ink being expended. I guess it's an easy story, and any speculation gets play.