India, Sept. 15 -- The letter arrived in Moscow not as diplomacy but as declaration. Kim Jong Un, writing to Vladimir Putin in reply to the Russian leader's congratulations on North Korea's 78th founding anniversary, named Russia's military operation in Ukraine something it had never been called in official Pyongyang communication at this level: a "sacred war." His support for it, he wrote, would not waver.

"Firmly convincing the victory of the Russian Federation in the present sacred war for defending the security interests of the country and international justice, I promise my invariable support to dear friend you and the fraternal Russian people," Kim wrote, according to North Korea's state news agency KCNA, which published the lette...