Are US-Israeli attacks against Iran legal under international law? | Israel-Iran conflict news

US and Israeli strikes against Iran, which have sparked a regional war, are likely to violate the UN Charter’s prohibition on aggression and have no valid legal justification, experts say.

“This is not legitimate self-defense against an armed attack by Iran and has not been authorized by the UN Security Council,” Ben Saal, the UN’s special rapporteur on the promotion of human rights and “counter-terrorism”, told Al Jazeera.

“Preventing disarmament, counter-terrorism and regime change is an international crime of aggression. All responsible governments must condemn this lawlessness by two countries that excel at shredding the international legal order.”

United States President Donald Trump’s administration has not received authorization for war — from the UN Security Council — or even from domestic lawmakers in Congress.

And Iran had not attacked the US or Israel before the strikes that killed Iran’s Supreme Leader Ali Khamenei and several other senior officials and hundreds of civilians.

Yusra Soodi, assistant professor of international law at the University of Manchester, said there were grounds to believe that the attacks against Iran constituted a crime of aggression.

“This is an act of illegitimate use of force,” Suidi told Al Jazeera.

International law is a set of treaties, conventions and universally accepted rules that govern relations between countries.

An imminent threat?

The Trump administration has argued that Iran poses a threat to the US through its missile program and nuclear program, arguing that military action is necessary.

But the UN Charter prohibits unprovoked attacks against other countries.

“All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any State, or in any manner inconsistent with the purposes of the United Nations,” the UN’s founding document states.

Rebecca Ingber, a professor at Yeshiva University’s Cardozo School of Law who previously served as an adviser to the US Department of State, said the prohibition on the use of force is a “bedrock” principle of international law that allows only limited exceptions.

“States cannot use force against the territorial integrity of other states except in two narrow circumstances – when authorized by the UN Security Council or in self-defense against armed attack,” Ingber said.

Sudy said an example of where the use of force may be legitimate is when a country tries to prevent an imminent attack by another state.

Trump said the goal of the war was to “protect the American people by removing imminent threats from the Iranian regime.”

But Sudi casts doubt on that proposition.

“The imminence in international law is really swift, overwhelming, leaving no choice but to act first, which is pretty much happening now,” Sudy said.

Trump himself has repeatedly said that a US attack on Iran in June 2025 would have “destroyed” the country’s nuclear program, and he noted that Tehran and Washington were in talks when the war broke out on Saturday.

“There was really no evidence of an imminent threat, and the attack was a preemptive strike,” Suidi told Al Jazeera.

“If it’s preemptive, it means you’re acting to deal with something in the future, hypothetical, speculative, and not imminent, but that’s exactly what happened here. That’s illegal under international law.”

U.S. officials, including Trump, have said Iran is building a ballistic missile arsenal to protect its nuclear program and then a nuclear bomb.

‘Scattershot’ arguments

Trump said he wanted “freedom” for the Iranian people as aides to the US president described the regime in Tehran as brutal.

In January, Iran responded to a wave of anti-government protests with a heavy security crackdown. The violence killed thousands.

Trump encouraged protesters to take over government buildings at the time, assuring them that “help is on the way.”

Humanitarian intervention to help protesters in Iran would have required UN Security Council approval to cross legal thresholds, experts say.

“The rationales are scattered,” Brian Finucane, senior adviser for the US program at the International Crisis Group, said of US justifications for the strikes.

“Certainly none of them amount to a serious international legal argument.”

Apart from possible violations of the UN Charter, US-Israeli attacks risk violating provisions of international humanitarian law intended to protect civilians from war.

An Israeli or US attack on a girls’ school in southern Iran’s Minab on Saturday killed at least 165 people, local officials said.

“Civilians are already paying the price for this military escalation,” Anne Scheel, US director at the Center for Civilians in Conflict (CIVC), told Al Jazeera in an email.

“We are seeing deeply alarming reports of attacks on schools and critical civilian infrastructure in Iran and across the region, with devastating casualties, including many children. These strikes risk igniting a broader regional catastrophe.”

Arms of military power

The attacks on Iran are the latest example of Trump relying on the brute force of US military power to promote his global agenda.

During Trump’s second term, the US has threatened to use military force to seize the Danish territory of Greenland, killed at least 150 people in an operation targeting drug-trafficking vessels in Latin America, and kidnapped Venezuelan President Nicolas Maduro in a military raid that killed at least 80 people.

The legality of all these policies has been questioned domestically and internationally, with UN experts saying the boat strikes amount to extrajudicial killings.

Trump told The New York Times in January that he is driven by his own morals.

“I don’t need international law. I’m not looking to hurt people,” the US president said at the time.

In recent years, both Democratic and Republican US administrations have continued to send billions of dollars in arms to Israel, despite the Israeli military’s genocidal war on Gaza, which has been documented by rights groups and UN experts.

Ingber, the law professor, said the deliberate use of military force has led to a sense of impunity for powerful states and undermined the international legal system that has been trying to place some restraints on conflict since the end of World War II.

“The ban on the use of force is a relatively recent innovation over the course of things. This rule is policed ​​through the actions and responses of states and is now weak,” he said. “Do we want to go back to a world where states can use force as a tool of policy?”

Iran itself has launched strikes against countries across the region in response to US strikes, launching missiles and drones at military bases and civilian targets – including airports, hotels and energy installations.

“In the case of war, from the moment the first strike is launched, they are clear that the laws of war apply and civilian objects and places cannot be targeted,” Sudey said.

He said Iran violated international law with its response.

Suedi told Al Jazeera that Russia’s invasion of Ukraine and Israel’s brutal invasion of Gaza show the “revealing fragility” of international law.

A war against Iran is “the next episode in that very worrying trend,” he said.