President Trump's threat to bomb Iran's water supply would constitute his most dramatic breach of the laws and norms designed to protect civilians in wartime.

Why it matters: The Iran war is the biggest test of what Trump's contempt for "politically correct" war-fighting looks like in practice.

His administration has already signed off on Israeli assassinations of political leaders, threatened "no quarter" for enemy combatants, and initially rejected responsibility for a mass casualty strike on an elementary school.
But the U.S. has been almost exclusively targeting Iran's military and nuclear program up to now.
The threat to hit civilian infrastructure shows how intent Trump is on finding ways to increase the pressure on Tehran, even if that means flouting the generally accepted principles of warfare.

Flashback: Trump criticized the Geneva Conventions during his 2016 campaign, lamenting that soldiers were "afraid to fight." He vowed to bring back waterboarding and "a hell of a lot worse."

Defense Secretary Pete Hegseth, then a Fox News host, spent Trump's first term lobbying privately and on air to secure pardons for soldiers convicted of war crimes.
Trump granted the pardons in 2019, citing Hegseth in his decision. In his 2024 book, Hegseth wrote that troops "should not fight by rules written by dignified men in mahogany rooms eighty years ago."

Driving the news: With the Iran war now entering its second month, Trump threatened Monday to "completely [obliterate]" Iran's power plants, oil wells and "possibly all desalinization plants" if a deal isn't reached soon.

Like other countries in the severely water-stressed region, Iran relies heavily on desalinated water.

What they're saying: "[Iran's] best move is to make a deal, or else the United States has capabilities beyond their wildest imagination," White House press secretary Karoline Leavitt said when asked about Trump's desalination threat.

"Of course this administration and United States armed forces will always act in the confines of the law, but with respect to achieving the full objectives of Operation Epic Fury, the president is going to move forward unabated," she added.
A senior U.S. official told Axios the idea was to use strikes to pressure Iran to negotiate. "The Iranians want this to stop, too. Don't be mistaken. Their economy is broken. A couple of sorties, they will have no power. A couple of Israeli sorties, they will have no water. There is a lot to lose if there's no accommodation. Everyone will have to give, but we can get there."
The official also cautioned that Trump has made no decision and "he wants to make sure that things are proportionate in this war. It's why he got mad when Bibi [Netanyahu] attacked the desalination plant in Iran a few weeks ago."
The Pentagon declined to comment for this story. The White House referred Axios to comments from Secretary of State Marco Rubio saying the operation was proceeding as planned and Trump has a "number of options available to him" to break Iran's hold on the Strait of Hormuz.

Zoom in: International humanitarian law explicitly prohibits attacks on objects indispensable to civilian survival, including drinking water installations. Power plants, by contrast, can be deemed lawful targets if they serve a military purpose.

Trump stated his intent plainly, writing that the strikes would be "in retribution for our many soldiers" that Iran has killed over the last 47 years.
Reprisals against civilians — also known as collective punishment — are explicitly prohibited under the Geneva Conventions.

Zoom out: Trump's desalination threat may just be rhetoric aimed at pressuring Iran into a deal. But it fits a pattern of statements and actions — many of them by Hegseth — that legal experts say contradict the laws of armed conflict.

At a Pentagon briefing on March 13, Hegseth declared "no quarter, no mercy for our enemies" — a phrase the Pentagon's own Law of War Manual describes as a war crime. He has not retracted it.
In the first months of the Trump presidency, Hegseth fired the top military lawyers for the Army, Navy and Air Force, saying he didn't want them to be "roadblocks to orders given by a commander in chief."
He has moved unsuccessfully to punish Sen. Mark Kelly (D-Ariz.) for a video advising troops to "refuse illegal orders."
Hegseth also dissolved the Pentagon's civilian harm mitigation program, which had embedded roughly 200 personnel across military commands to prevent civilian casualties.

That decision drew fresh scrutiny after a U.S. airstrike on the first day of the war killed more than 165 people — most of them girls — at an elementary school in the southern Iranian city of Minab.

Trump initially denied U.S. responsibility, falsely suggesting Iran or some other party had obtained Tomahawk missiles.
A preliminary Pentagon investigation found the U.S. was responsible, according to media reports, but no official results have been released.

Between the lines: Iran is where Trump's "might makes right" doctrine is most visible. But it has been the operating assumption across every theater where the administration has used force.

The U.S. has killed more than 160 people in strikes on alleged drug trafficking boats in the Western Hemisphere since September 2025, offering little public evidence to justify the targeting.
The Trump administration also made its feelings toward international war crimes law clear last year when it sanctioned officials from the International Criminal Court for investigating U.S. and Israeli nationals.