In a recent Financial Times interview, Donald Trump warned NATO allies that refusing to join a U.S.-led naval coalition in the Strait of Hormuz would carry serious consequences for the alliance. He suggested that American assistance to partners over Ukraine could be curtailed if allies do not reciprocate by helping “knock out some bad actors” along Iran’s shore. The veiled threat: reduce support for Kyiv, including limiting arms transfers, to compel participation.
That line of pressure creates a stark dilemma for NATO. The alliance’s current posture is designed to keep consistent pressure on Russia and sustain support for Ukraine until U.S. policy is more favorable to Kyiv. Yet few European governments want to expose their forces to direct confrontation with Iran at sea, where a mass-casualty incident would produce explosive domestic backlash and could end political careers. Military involvement in the Hormuz chokepoint risks escalation, casualties, and an unpopular long-term engagement.
Saying no, however, is not cost-free. Blocking or refusing to participate in coalition operations in the strait would likely keep oil prices high, heightening economic strain and political pressure at home across Europe. It could also make Washington more inclined to take steps Europe opposes, such as extending waivers or tolerating energy flows from Russia to blunt price shocks. The strategic calculus thus forces NATO to trade military risk in the Gulf against economic and reputational pain in Europe and a potential weakening of ties with Washington.
A complete U.S. military withdrawal from Europe if NATO rejects the plan remains unlikely, so the immediate security cost is limited. The harder test would be whether European governments could politically justify reversing anti‑Russian energy policies—reopening pipelines or buying more Russian oil—to shield their populations from higher prices. Even such measures might not prevent a strategic setback in Ukraine if Washington chooses to shift attention or resources to Iran.
Worryingly, an American president willing to accept or tolerate a Russian advantage in Ukraine in exchange for gains elsewhere could make this trade-off real. Moscow might offer terms or détente that appeal to a U.S. administration focused on preserving other interests, and that dynamic could tempt a transactional approach to both Iran and Russia.
For NATO the prudent course is to prepare for multiple outcomes. If the alliance declines to join a Hormuz coalition, leaders should plan for economic fallout, coordinate emergency energy measures, harden domestic political messaging, and intensify diplomatic efforts to keep Western support for Ukraine intact. If allies do join, NATO must protect and prioritize weapons and funding flows to Kyiv, mitigate diversion of materiel and attention, and prepare contingencies for escalation with Iran.
Ultimately NATO faces a choice between short-term military risk in the Gulf and longer-term political, economic, and strategic risks if it refuses. The alliance’s response should combine contingency planning, energy resilience, and clear coordination with Washington to avoid being forced into a zero-sum decision that undermines European security or the campaign to support Ukraine.
