Strategic Costs and Russia’s Shifting Calculus on Nuclear Assistance to North Korea *

Is Russia likely to provide sensitive nuclear assistance to North Korea?Drawing on the strategic theory of nuclear proliferation, this article explains why Moscow withheld such assistance for four decades and why the structural conditions that underpinned that policy have now eroded.During the Cold War, the Soviet Union restrained North Korea's nuclear program because proliferation would have undermined its own security, regional influence, and alliance control.In the post-Cold War period, Russia's decline reduced these costs, but fears of regional instability and reactive proliferation still discouraged nuclear assistance.Since 2017, two structural changes have altered this calculus.First, North Korea's achievement of a minimal nuclear deterrent means further assistance would impose few additional costs on Russia's already limited leverage.Second, Russia's intensifying confrontation with the United States has increased the strategic value of North Korea's nuclear advancement as a tool for imposing costs on Washington.