MOSCOW, Sept. 25 -- Vladimir Putin has been waiting more than five weeks for Kim Jong Un to name a date. Donald Trump has been waiting the same five weeks for the same thing. On Thursday, only one of them got an answer.

Russian Deputy Foreign Minister Andrei Rudenko told TASS that Kim has been formally invited to visit Russia, with the timing to be "agreed through diplomatic channels." "Chairman Kim Jong-un has been invited to visit our country," Rudenko said. "Russia will always welcome the leader of the Democratic People's Republic of Korea." No date was given. None was needed. The invitation itself was the message.

That message lands inside a relationship that has already moved well past the stage of formal gestures. North Korea has ...