"This is transactional diplomacy at its worst," said one senior EU diplomat, speaking on condition of anonymity. "We're being told to choose between defending Ukraine and getting dragged into a war in the Gulf that we never asked for."

The threat exposes the fundamental vulnerability at the heart of Europe's security architecture. Despite decades of talk about "strategic autonomy," European defense remains overwhelmingly dependent on American weapons, intelligence, and logistical support. Washington provides roughly 60% of military aid to Ukraine, including critical air defense systems, long-range missiles, and satellite intelligence that European militaries cannot match.

Trump's willingness to weaponize that dependence has sent shockwaves through European capitals, particularly in Warsaw, Vilnius, and Tallinn, where the specter of Russian aggression looms large. Poland has spent heavily to reach 4% of GDP on defense - double the NATO target - specifically to maintain strong ties with Washington. Now that investment looks increasingly fragile.

The European Commission declined to comment directly on the Financial Times report. But Commission President Ursula von der Leyen, speaking at a press conference in Brussels, emphasized that "Europe's support for Ukraine is unwavering and unconditional."

That support, however, cannot fully compensate for American capabilities. Europe has struggled to deliver even basic ammunition - the much-touted Czech ammunition initiative to provide 500,000 artillery shells remains underfunded and behind schedule. European defense industries, hollowed out by decades of underinvestment, simply cannot produce weapons at the scale Ukraine requires.

The crisis has revived long-dormant discussions about European defense integration. French President Emmanuel Macron has called repeatedly for a "European defense union" that could operate independently of Washington. But such proposals face fierce resistance from Central and Eastern European states that view American security guarantees as irreplaceable.

"We've been warning about this for years," said Nathalie Tocci, director of the Istituto Affari Internazionali in Rome. "Europe kept saying it wanted strategic autonomy while doing nothing to build the actual capacity. Now we're paying the price."

The Strait of Hormuz demand is particularly awkward because it requires Europe to choose sides in a conflict where many member states see American policy as reckless. Germany, Spain, and Ireland have all expressed reservations about the Trump administration's military strikes against Iran. Joining a U.S.-led naval mission would effectively endorse a war most Europeans oppose.

Yet refusing could mean watching Ukraine collapse for lack of American weapons - a scenario that would embolden Moscow and potentially invite Russian aggression against NATO's eastern flank.

Brussels decides more than you think. But in this case, Brussels isn't deciding anything - it's being forced to choose between two catastrophic options, both dictated by Washington. That's not strategic autonomy. That's strategic dependence with a gun to your head.