Nina L. Khrushcheva is a professor of international affairs at the New School and the co-author of In Putin’s Footsteps: Searching for the Soul of an Empire Across Russia’s Eleven Time Zones. When North Korean leader Kim Jong-un stepped out of his armoured train at a railway station in the eastern Russian town of Khasan for his recent meeting with President Vladimir Putin, I could not help but think of the satirical 2017 film The Death of Stalin. The miniature bridge from the platform to the station and the feeble red runner along which Mr. Kim strode stood in comical...