In a recent Financial Times interview, Donald Trump warned that if NATO members decline to join a US-led naval effort to secure the Strait of Hormuz, Washington’s support for allies — including aid to Ukraine — could be at risk. He framed the choice starkly: the US has helped Europe on issues far from its borders, he said, and may expect reciprocal help when it asks. The warning carried an implicit threat that Washington could curb assistance to Kyiv, for example by restricting arms transfers, if allies refuse to participate in operations to “knock out some bad actors” along Iran’s coast.
That demand puts NATO in a difficult bind. For months the alliance’s strategy has been to sustain Ukraine’s resistance until a US administration more hostile to Russia returns to power. Yet joining a military effort in the Gulf would expose allied forces to direct confrontation with Iran, raising the prospect of casualties that could provoke domestic backlash and damage political careers across capitals. If NATO refuses, however, the alliance risks eroding American commitment to Ukraine and making Kyiv’s fight much harder to sustain.
There is also a significant economic dimension. A failure to reopen the strait or otherwise contain disruption could keep global oil prices elevated, inflicting pain on ordinary consumers in allied countries. Paradoxically, higher energy prices might increase pressure in Washington to extend temporary waivers on sanctions that restrict Russian oil — a move the EU opposes — further complicating allied cohesion. European governments must therefore weigh the immediate military and political costs of a Gulf intervention against the longer-term economic and reputational costs of inaction, including a greater chance of Russian gains in Ukraine.
Some mitigating factors limit the downside of refusal. The US is not widely expected to pull all its forces out of Europe if NATO declines to join the Hormuz coalition, so the most extreme military consequences are unlikely. Europe could also blunt energy-price shocks by loosening restrictions on Russian supplies — for instance, by buying more Russian oil or reopening pipelines — though doing so would carry heavy political costs and further strain transatlantic relations over Russia policy.
Perhaps the biggest risk, however, is political: a sustained weakening of Western support for Ukraine could allow Russia to make meaningful territorial or diplomatic gains. While that outcome might seem to run counter to Trump’s interest in a lasting legacy as a dealmaker, it is plausible he would accept or even encourage a softer US posture toward Moscow if Russia helped achieve US aims vis-à-vis Iran or if a reduced transatlantic partnership served as retribution for European non-cooperation. Putin could also offer economic incentives, such as energy or resource agreements, to smooth a post-conflict rapprochement with the United States.
NATO therefore faces two unpalatable options. It can join a risky confrontation with Iran — diverting resources and political capital away from Ukraine and taking on the danger of allied casualties — or it can refuse and face the economic pain of higher energy prices, a strained relationship with the United States, and an increased chance of Russian advances in Ukraine. Either choice would offer Moscow an opening: Western redirection of arms and attention would enable Russia to pressure Kyiv more effectively and extract concessions.
Allies should prepare for both scenarios. That means clarifying limits and expectations on any proposed Gulf mission, reinforcing contingency plans to sustain Ukraine if US support wavers, and considering energy and diplomatic steps that could mitigate economic fallout without surrendering core political principles.
Originally published on Andrew Korybko’s Substack; republished here with edits for clarity and an update on Trump’s response on Friday.
