How the Russia-North Korea Axis Is Undermining Trump’s Global Defense Doctrine

That premise is breaking under the weight of a Russian–North Korean operational partnership that refuses to respect the boundaries Washington's strategy depends on.

The doctrine and its friction

The 2025 National Security Strategy formalizes "burden-sharing and burden-shifting," asking wealthy allies to assume primary defense responsibility for their own theaters so the United States can function as "convener" and "supporter" of a broader network. The 2026 National Defense Strategy specifies the assignment with unusual precision: European allies take primary responsibility for Europe's conventional defense and the lead in supporting Ukraine; South Korea is described as capable of taking primary responsibility for deterring North Korea, with "critical but more limited" U.S. support.

The framework is intellectually elegant. It is also, as the Foreign Policy reporting makes clear, structurally fragile. President Donald Trump's decision last week to scale down the annual Ulchi Freedom Shield exercise with South Korea coincided with Russian forces using North Korean ballistic missiles against the Ukrainian city of Zaporizhzhia, and Pyongyang launching another ballistic missile from its east coast. South Korea cannot effectively deter a North Korea that is being upgraded in real time on a Ukrainian battlefield. Europe cannot lead on conventional defense against a Russia that is, simultaneously, being reinforced by Pyongyang. The two theaters share a supply line, and the doctrine assumes they do not.

What we should watch

Three indicators will determine whether the strategy holds or collapses into cascading burden-shifting. First, whether Seoul formally responds to Ukrainian President Volodymyr Zelensky's appeal for help strengthening Ukraine's air defenses—evidence that South Korea is internalizing the linkage between its theater and Europe's. Second, whether the scaled-down Ulchi iteration produces documented gaps in the drone, GPS-disruption, and cyberattack scenarios planners had built into this year's exercise, given that those contingencies were calibrated to a North Korea accumulating wartime experience from Russia's invasion. Third, whether the 2026 NDS allocation for "critical but more limited" U.S. support to South Korea translates into deployable hardware rather than doctrinal language.

The European mirror

The same logic that complicates Seoul's position is reshaping European force planning from the ground up. According to the Center for European Policy Analysis, British Army Chief of Staff Gen. Roly Walker told the UK-commanded Allied Rapid Reaction Corps in June that it must be capable of what a Ukrainian corps can do today: persistent mid- and deep-range strikes that stretch Russian front lines and dismantle mobilization attempts. New British acquisitions, including autonomous and remote systems, are being deployed to the alliance's eastern flank over the coming year with a stated readiness window of under thirty minutes. The Netherlands is assigning around 600 personnel to drone operations. France has ordered 5,000 low-cost soldier drones after testing the first 1,000 during Exercise Orion. Britain's emerging 20:40:40 approach to combat power—heavy on autonomous and reusable equipment—is the doctrinal fingerprint of the same lesson now propagating across the continent.

Europe and South Korea are converging on a shared conclusion from different directions: deterrence now requires mass, autonomy, and short adaptation cycles, not expensive platforms. The unresolved variable is whether "burden-shifting" was ever compatible with that requirement, or whether it simply exports the cost of preparing for the next war while keeping the United States one step removed from the one already underway.