• “A very smart and gracious gesture.”

That was President Trump on Twitter, praising North Korea’s vow to demolish its nuclear test site this month. (Some analysts say the site, in a mountain, above, is too unstable for another test anyway.)

Mr. Trump also exulted in the release of three Americans from North Korea last week. They join more than a dozen other former prisoners, who told us how freedom brought its own problems.

As Mr. Trump prepares to meet North Korea’s leader, Kim Jong-un, on June 12, China may hold the cards. It has the most leverage on the North, and wants to reward it for each step toward nuclear disarmament — an approach the White House rejects.