The USSR had plenty of military hardware with which to equip the North Korean army. However, Stalin sought to keep Moscow in the background. He wanted to avoid a confrontation with the United States and entangle the People’s Republic of China in the conflict. The latter increased the PRC’s reliance on Moscow and share of the war’s costs.
Soviet control loosened after Stalin’s death and the end of the war. Although the Soviet Union remained the North’s more powerful neighbor, Beijing had rescued Kim from otherwise certain military defeat. Moreover, Kim Il-sung particularly disliked Nikita Khrushchev’s destalinization program.
Kim Il-sung played his two large neighbors against each other. Observed Fyodor Tertitskiy of NKNews: “North Korea deftly exploited this diplomatic game. For the entire Cold War, Pyongyang successfully milked the Kremlin for resources, with offering nothing but smiles and talk of friendship in return. The fact that the same line was pursued towards Beijing was a small consolation.”
China also suffered tensions in its relationship with the Democratic People’s Republic of Korea but enjoyed greater influence in Pyongyang. Especially important, the PRC came to dominate North Korea’s external economic relations after the former’s economic takeoff.
Later the DPRK reacted badly when after the Soviet Union’s collapse the newly constituted Russian government opened diplomatic relations with the Republic of Korea. Although China eventually followed suit, the North’s reaction then was more muted, presumably because it would not have been wise to offend both of its occasional patrons. China’s and Russia’s relative status in Pyongyang were highlighted in 2018 by the summit between Kim Jong-un and former president Donald Trump. The summit triggered five visits between Kim Jong-un and the PRC’s Xi Jinping but only one three-hour, mostly symbolic meet-and-greet with Russia’s Vladimir Putin.
Although Moscow’s relations with North Korea still matter less than those that North Korea maintains with China, the former retains veto power over United Nations sanctions and is the source of some hard currency for financially strapped Pyongyang. However, Russia appears to genuinely oppose a nuclear North, which is hardly surprising since North Korea’s growing arsenal makes that state more independent from all its neighbors, including its nominal friends. Recent estimates from the Rand Corporation and Asan Institute are particularly sobering for Moscow. Within a few years, Pyongyang could possess a couple of hundred nukes, making it a mid-level nuclear power. For Moscow, both shaping North Korea’s behavior and coping with its collapse would become much more challenging.