Explainer: Why Trump’s Iran threats are raising war crimes concerns

• President Trump threatened Iran with bombing civilian infrastructure if the Strait of Hormuz is not reopened, raising war crime concerns.
• Prosecution of Mr Trump is unlikely due to US Supreme Court immunity ruling and the US not being an ICC member.
• Attacks on civilian infrastructure violate the Geneva Conventions, but proving intent and proportionality is complex.

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GENEVA – By warning that the United States would deliberately bomb civilian infrastructure in Iran and effectively bring the country to its knees if officials there do not reopen the Strait of Hormuz, President Donald Trump drew criticism that he was threatening to commit war crimes.

His comments also raised questions about whether he could ever be punished for such conduct.

War crimes, in theory, can be prosecuted under US law or by the International Criminal Court (ICC), a tribunal for holding accountable the worst offenders of international law.

In reality, Mr Trump would almost surely be protected from prosecution in the US over such actions following the Supreme Court’s 2024 decision granting absolute immunity to the president over his official conduct in office.

Prosecution by the ICC would be equally unlikely because the US is not a member of the court.

What has Mr Trump threatened?

On March 30, Mr Trump posted on social media that if the Iranians do not reopen the Strait of Hormuz, the US would retaliate by “blowing up and completely obliterating all of their electric generating plants”, as well as their oil wells and “possibly all desalinisation plants”.

In an address to Americans on April 1, he said the US would soon meet its military objectives.

“We’re going to bomb them back to the Stone Ages, where they belong,” he said.

On April 5, in an expletive-laden post, he said Iranians would be living in “hell” if their government does not relent. The next day, he said “they’ll have no bridges”. And then, “the entire country can be taken out in one night”.

Senator Chuck Schumer, leader of the Democrats in the Senate, said in a social media post on April 5 that Mr Trump was “ranting like an unhinged madman” and “threatening possible war crimes”.

Iranian civilian infrastructure, including apartment blocks, roads and ports, has already been hard hit by the US-Israeli military offensive that began on Feb 28. But the destruction of Iran’s power plants will cause much greater devastation, impacting everything from running water to hospital emergency rooms.

From the start of the war, Iran has also attacked civilian infrastructure across the Middle East, including energy infrastructure, ports and airports.

Mr Trump’s threatened escalation could trigger a similar response from Iran, sparking a massive intensification of hostilities.

What are war crimes?

They are violations of the rules of warfare as set out in various treaties, notably the Geneva Conventions, a series of agreements concluded between 1864 and 1949.

War crimes include torture, rape, using starvation as a weapon, shooting combatants who have surrendered, deploying banned weapons such as chemical and biological arms, and deliberately attacking civilians.

It can also be a war crime for a military to target civilian infrastructure because doing so can punish non-combatants.

A 1977 supplement to the Geneva Conventions known as Protocol I states that civilian facilities and infrastructure “shall not be the object of attack or of reprisals”, though they can be legitimate targets if the facilities are significantly aiding the enemy.

The protocol says that “military objectives are limited to those objects which by their nature, location, purpose or use make an effective contribution to military action and whose total or partial destruction, capture or neutralisation, in the circumstances ruling at the time, offers a definite military advantage”.

When there is doubt about whether civilian infrastructure is being used by a military, the protocol holds that “it shall be presumed” that it is not.

What do legal experts say about Mr Trump’s threats?

Professor Rebecca Hamilton, at American University’s Washington College of Law who formerly served as a lawyer in the ICC’s prosecution division, said infrastructure that appears civilian on its face could in fact be “dual purpose”, meaning it could potentially be targeted without it being a war crime.

Still, she noted, the rule of proportionality applies, meaning the expected harm to civilians cannot be excessive compared to the military advantage anticipated. And precautions must be taken to ensure targets are selected carefully.

“The laws of war are oriented around protecting civilians,” she said. “One of the foundational principles of international humanitarian law is that you must distinguish between military and civilian people and objects, and only target the military ones.”

Mr David J. Scheffer, who was a US ambassador at large for war crime issues during the administration of former president Bill Clinton, said Mr Trump’s comments about bombing Iran could undermine arguments that civilian infrastructure represents valid military targets.

Mr Scheffer, now a senior fellow at the non-partisan think-tank Council on Foreign Relations, pointed to Mr Trump’s “Stone Age” remark.

“Hitting power plants and desalination plants, for example, may be connected to some plausible military advantage, but that’s a very hard test to satisfy, and the details matter,” he said. “Ordering a Stone-Age obliteration of a country’s civilian infrastructure would defy the proportionality test in the law of war and international humanitarian law.”

How are war crimes prosecuted in the US?

War crime prosecutions against members of the US military are typically carried out under the Uniform Code of Military Justice, approved by Congress to enforce discipline and accountability in the armed forces.

Alleged violations of the uniform code result in military trials that can result in a court martial.

Cases can also be prosecuted under the War Crimes Act of 1996, though they are exceedingly rare.

In the first prosecution under the law, the Justice Department in December 2023 brought criminal charges against four Russia-affiliated military personnel for allegedly torturing a US citizen in Ukraine.

The case fell within the jurisdiction of the law because the alleged crimes were committed against a US citizen.

Such a case would be all but impossible against Mr Trump. A president’s orders to the military as commander-in-chief would fall squarely within the immunity the Supreme Court, in its 2024 ruling, afforded to official actions of the US leader.

The Supreme Court’s ruling does not apply to other administration officials or members of the military.

However, war crime cases against such individuals could be undermined before they ever started if a president were to issue broad pardons to anyone involved, much as Mr Trump did with participants in the attack on the US Capitol on Jan 6, 2021.

How does the ICC prosecute war crimes?

The Hague-based ICC was established by a treaty called the Rome Statute in 2002 – 125 countries have ratified the treaty to become ICC members.

The court has a prosecutor who can investigate and propose charging individuals with war crimes, as well as crimes against humanity, genocide and the crime of aggression.

The prosecutor must first ascertain that domestic legal systems are not “genuinely” seeking justice.

The ICC can pursue war crime cases when the alleged offences were committed by a citizen of a member state, or in the territory of a member, or in a state that has accepted the court’s jurisdiction, or when the UN Security Council requests a probe.

Could the ICC pursue war crimes committed in the Iran war?

That would be a challenge, given that Iran, the US and Israel have not joined the ICC.

The US could be counted on to veto any UN Security Council resolution calling for an investigation. In theory, Iran could accept the court’s jurisdiction. But doing so would subject its attacks on civilian sites to ICC scrutiny, too.

In the event of an investigation resulting in an arrest warrant for Mr Trump or other US officials, the ICC would likely find it difficult to execute such an order.

To make arrests, it relies on member states, which means that those it accuses can evade capture by avoiding travel to a country that might turn them over.

Plus, member states do not always honour warrants. Mongolia, for example, failed to enforce an ICC arrest warrant for Mr Vladimir Putin for alleged war crimes in Ukraine when it welcomed the Russian President in September 2024.

Hungary in April 2025 similarly welcomed Israeli Prime Minister Benjamin Netanyahu, subject of a warrant for alleged war crimes in the Gaza Strip, and quit the court.

The ICC does not permit trials in absentia.

What’s the history of the ICC?

In an early exercise of international criminal justice, Allied powers tried and punished German and Japanese leaders after World War II, sentencing some to death.

Because the Allies granted themselves immunity from war crime charges, the tribunals were criticised as victors’ justice. To avoid that conflict of interest, the UN Security Council created independent, international tribunals to prosecute atrocities in the Balkans and Rwanda in the 1990s.

Those horrors revived a 19th-century idea of establishing a permanent world court to hold people accountable for acts of mass inhumanity, giving rise to the ICC. BLOOMBERG