President Donald Trump’s repeated threat to destroy Iranian civilian infrastructure is the latest sign of the U.S. leader’s increasing detachment from international norms and the bounds of modern warfare, a trend that’s alienating traditional allies.

Trump has pushed into legally contested territory both abroad and at home in his second term, advancing an expansive view of presidential authority. That’s included seizing Venezuela’s president and taking control of the country’s oil, bombing half a dozen nations including Nigeria, and starting the Iran war without Congressional approval, sparking a global energy crisis.

Europeans have balked at joining the U.S. campaign — which shows no sign of ending — refusing the use of some military bases and ignoring Trump’s calls to help reopen the Strait of Hormuz, a vital waterway for energy supplies. But his latest threats to explicitly target essential infrastructure have alarmed countries already shaken by his assault on the world order and disdain for international law.

The U.S. will “blow up and completely obliterate all of their Electric Generating Plants, Oil Wells and Kharg Island (and possibly all desalinization plants!)” if Iran does not reopen Hormuz, Trump said in a March 30 social media post. In a Wednesday address to Americans, he said the U.S. would bomb Iran “back to the stone ages, where they belong,” and repeated his threat against its power plants.

The U.S.-Israeli bombing campaign that began on Feb. 28 has already destroyed Iranian civilian infrastructure — including apartment blocks, roads and ports. Israeli strikes have targeted organs of the state, and destroyed fuel depots and police stations. But the destruction of its power plants would cause untold devastation — impacting everything from running water to hospital emergency rooms — and wreak further havoc on the daily lives of ordinary Iranians.

It would also likely trigger a response from Iran against U.S. Gulf allies’ civilian infrastructure, sparking a massive escalation in the war, potentially drawing in those Arab countries and leading to further turmoil in global energy markets.

Asked about Trump’s threats against Iran’s civilian infrastructure potentially being war crimes, White House Press Secretary Karoline Leavitt said Monday that the administration and U.S. forces would “always act within the confines of the law,” but that Trump would move forward “unabated.”

European diplomats, speaking on condition of anonymity to discuss sensitive matters, said their countries are increasingly alarmed by Trump’s threats, which one characterized as grossly disrespectful of international law. Another added that Trump was unlikely to carry them out because such attacks would irreversibly damage Washington’s reputation as a global leader.

U.K. officials said Trump’s actions would be illegal if carried out, adding that such an escalation would worsen the economic impact of the war. A European official said if Trump followed through, it’d risk being compared with Russia’s attacks on Ukrainian civilian infrastructure, which European Union countries have widely condemned.

Such threats undermine the rules the U.S. has used to challenge Russia in Ukraine and China in the South China Sea, weakening its ability to enforce them, according to experts on international law.

“An order to ‘obliterate’ ‘all’ power plants or desalination plants — such as the threat here — would certainly violate the law of armed conflict,” said Rebecca Ingber, a Cardozo Law School professor and former Counselor on International Law at the State Department. “It will be a much more chaotic and dangerous world if we tear down the legal frameworks governing war and the use of force that we worked so hard to enshrine.”

Since the war began more than a month ago, Iran has attacked civilian infrastructure across the Gulf, including energy infrastructure, ports and airports, in what experts say are also potential war crimes.

Spanish Prime Minister Pedro Sánchez has called the war “illegal,” while U.K. Defence Secretary John Healey said it is for Washington to “set out the legal basis” for its actions.

Since then, a series of U.S. attacks — including an alleged strike on a school in Iran that killed scores of children that Washington said it’s investigating, and the sinking of an Iranian naval vessel in the Indian Ocean near Sri Lanka — have intensified concerns about how the war is being fought.

Secretary of Defense Pete Hegseth has urged U.S. troops to pursue “maximum lethality” and scrap what he called “politically correct and overbearing” rules of engagement. He’s also dismantled the Pentagon’s Civilian Protection Center of Excellence, which advised commanders on limiting noncombatant casualties.

Asked on Tuesday about the president’s threats against desalination plants, Joint Chiefs Chair Dan Caine said the military has “numerous processes in system to carefully consider the whole range of considerations, from civilian risks to legal considerations, with any target.”

“As targets come before us, we run them through the same process that we always do and always strike lawful targets,” he added.

The U.S. is not a member of the International Criminal Court and doesn’t accept its jurisdiction, but it remains bound by the Geneva Conventions and customary international law governing armed conflict.

Some former Republican officials dismiss legal concerns as a distraction, pointing to Iran’s targeting of civilian infrastructure across the Gulf. The U.S. has also justified the current war by citing Iran’s many decades of support for proxy militant groups across the Middle East — including Hamas in Gaza, Hezbollah in Lebanon and militias in Iraq — that have attacked U.S. troops, diplomatic buildings and Israel.

“It is Iran’s actual war crimes, not prospective American actions, that will most concern U.S. partners in the region and should most concern legal scholars,” said Michael Singh, a former senior director for the Middle East at the National Security Council under George W Bush.

Desalination plants are treated under the laws of war as essential to civilian survival and cannot be attacked if doing so would deprive populations of water.

Iran uses desalination plants for very little of its drinking water. But the greater risk is the precedent it would set: Tehran is likely to respond in kind, putting far more vulnerable Gulf states at risk — Kuwait depends on such facilities for about 90% of its drinking water. That figure is 86% in Oman and 70% in Saudi Arabia.

Iran has accused the U.S. of hitting one of its desalination facilities on Qeshm Island in the Persian Gulf, which Washington denied. Following that incident, Bahrain said Iran struck one of its desalination plants.

Power plants are more legally contested, but strikes on energy infrastructure are still prohibited if the foreseeable harm to civilians — including the loss of electricity, water and other essential services — outweighs any military gain.

The legal risks for Trump himself are limited. In practice, it’s hard to see an international court acting directly against him, and presidents have broad latitude as commander in chief.

But Adil Haque, a professor at Rutgers Law School, said Trump’s latest threats may themselves be illegal because they appear aimed at coercion of civilian populations and collective punishment, both prohibited under the laws of war.

“President Trump appears to be threatening to attack these sites in pursuit of political advantage in negotiations, and as a form of collective punishment of the civilian population for the past actions of their government,” he said. “This is manifestly unlawful.”

----------

—With assistance from Ellen Milligan, Mirette Magdy, Alex Wickham, Marie Patino and Iain Marlow.

©2026 Bloomberg L.P. Visit bloomberg.com. Distributed by Tribune Content Agency, LLC.