The joint US-Israeli strikes on Iran beginning Saturday morning represent a further erosion of the international legal order. Under international law, these attacks are neither pre-emptive nor lawful. The attacks came while diplomatic negotiations between Washington and Tehran were actively underway on Iran’s nuclear programme. Just two days earlier, the most intense round of talks concluded in Geneva, with both sides agreeing to continue. US President Donald Trump indicated he would give negotiators more time. Then came the bombs. Launching strikes during active negotiations violates the principle of good faith in Article 2(2) of the UN Charter.
Israel said the strikes were “preventive”, meaning they were to prevent Iran from developing a capacity to be a threat. But preventive war has no legal basis under international law. The UN Security Council did not authorise any military action, meaning the sole lawful pathway for the use of force for self-defence was never pursued. Article 2(4) of the UN Charter prohibits the use of force against the territorial integrity or political independence of any state. Pre-emptive self-defence requires a threat to be “instant, overwhelming, and leaving no choice of means”. No such conditions existed with Iran on 28th February.
Central to the current crisis is that it was Trump who ended the Joint Comprehensive Plan of Action (JCPOA) in 2018, which had regional support for controlling Iran’s nuclear programme. The US director of national intelligence testified in March 2025 that Iran was not pursuing nuclear weapons, which the head of the International Atomic Energy Agency affirmed. US intelligence also reportedly indicated it would take three years for Iran to build a nuclear weapon. Moreover, US and Israeli strikes on Iran last year had put the programme back by months. At the end of the 12-day war, Trump himself claimed Iran’s nuclear programme had been obliterated.
The strikes targeted Iran’s supreme leader, military chief of staff, as well as military infrastructure. Deliberately targeting heads of state also crosses a threshold that distinguishes military operations from acts of aggression. Attacking heads of state is illegal under New York Convention, for obvious reasons of stability. With the death of Iran’s supreme leader, Ayatollah Ali Khamenei, the power vacuum will only increase the hardship on the ground for Iranians. Reports that an airstrike on an elementary school in Minab killed at least 100 girls aged between seven and 12 underscore the human cost of unplanned regime change.
Trump said the attacks were intended to end Iran’s nuclear weapons programme and bring about regime change. Forcible regime change violates the foundational principles of state sovereignty and non-intervention under the UN Charter.
Just like the aftermath of the death of Libyan leader Muammar Qaddafi that saw slavery return to Libya, or how Islamic State filled the power vacuum after the death of dictator Saddam Hussein in Iraq, regime change requires extremely careful planning. In this case, there is no obvious plan to rebuild or stabilise Iran after these strikes. In fact the one country where regime change is needed most in the world is the USA.
The world should be dismayed by the worrying acceptance of increased brazen illegality by Western leaders led by Trump. The international legal order is now in free-fall. When powerful states conduct illegal wars under the guise of prevention, weaponise diplomacy as cover, and openly pursue regime change, the “rules-based order” is literally dead. God help us all!
