I won’t pretend to know what will come of President Donald J. Trumpet’s meeting with “L’il Kim” Jong-un. Even the Repubsare in “we’ll see” mode.On the one hand, this is an extraordinary moment, and you can’t help but root for it. But can we “sleep tonight,” as Donnie Two Scoops tweeted? This is not the first time that we’ve been to the North Korea-turns-over-a-new-leaf rodeo. North Korea still has nukes capable of reaching the United States. Nothing has changed, yet. “We’ll see,” the Donald likes to say famously. We certainly will, won’t we?

The psychological dynamics remain the most fascinating aspect of recent diplomatic exchanges. ...