SEOUL, South Korea — Guess what country just issued stamps of Donald Trump? North Korea! Yes: An official postage stamp features grave-looking likenesses of President Trump and Kim Jong-un, the leader of North Korea, standing side by side. It commemorates their pleasantry-laden chitchat earlier this summer at Panmunjom, in the Demilitarized Zone between the two Koreas.

Why is North Korea celebrating that moment as “historic” (Mr. Kim’s own word)? Because it has to. After Mr. Kim scurried down to get whatever face time the American would grant him, the scene had all the makings of a public humiliation. So the North Koreans are now aggressively pretending that the encounter was somehow a coup for Mr. Kim.

And Panmunjom is only his latest misstep this year. North Korea makes its living off nuclear brinkmanship — and it has been firing missiles repeatedly in recent weeks — but lately its Dear Respected leader has been on a losing streak in that racket. For perhaps the first time in living memory, Team Kim is being outmaneuvered by the Americans in their zero-sum contest.

Let’s start with the Panmunjom blunder. The first rule of North Korean diplomacy is that Pyongyang controls everything — the venue, the timing, the agenda, the invitees — otherwise there are no meetings. Yet in June, with a seemingly offhand tweet suggesting a last-minute encounter at the DMZ, Mr. Trump upended 70 years of North Korean protocol. Within hours, Mr. Kim’s minions promised that their man would show. The American president came, he saw and he left without making any concessions.