United States President Donald Trump is considering joining Israel in what it claims are its efforts to destroy Iran’s nuclear programme, based on its stated belief that Iran is “very close” to developing a nuclear weapon.
Israel argues that it has carried out attacks on Iran’s military and nuclear sites over the past week in anticipation of an Iranian nuclear attack. But is this a valid justification?
The United Nations Charter, which is the founding document for states’ rights since World War II, outlaws aggressive war, allowing military action only as self-defence.
Only the UN Security Council is empowered to decide if military action is justified, once countries have tried and failed to resolve their differences peacefully.
If a country is attacked while the UNSC deliberates, that country still has the “inherent right of individual or collective self-defence”, however.
The question of the legality of Israel’s strikes on Iran, therefore, revolves around whether Israel – and any allies coming to its aid – can justify its attacks on Iran as “anticipatory” self-defence.
“This is not a situation in which Israel is allegedly responding to an Iranian attack occurring now, whether directly or through proxies such as the Houthis,” wrote Marko Milanovic, a professor of public international law at Reading University who has served on the International Criminal Court (ICC), in the European Journal of International Law, which he edits.
Israel cannot make the case that an attack is imminent, argued Milanovic.
“There is little evidence that Iran has irrevocably committed itself to attacking Israel with a nuclear weapon, once it develops this capability,” wrote Milanovic.
“And even if such an intention was assumed – again, it would be for Israel to provide any further evidence of such intention – I don’t see how it could plausibly be argued that using force today was the only option available.”
“Even if the broadest possible [legally plausible] understanding of anticipatory self-defence was taken as correct, Israel’s use of force against Iran would be illegal,” he concluded.
The United Kingdom’s chief legal counsel, Richard Hermer, advised Prime Minister Keir Starmer against getting involved in any attack on Iran, “unless our personnel are targeted”, according to Sky News.
“The possibility of acting in self-defence in view of an attack that might be coming is illegal in international law and we’re all very, very clear about that,” agreed Maria Gavouneli, a professor of international law at Athens University.
She said nuclear weapons have been discussed in international legal circles as a special case.
“There might be a chance for anticipatory self-defence, in other words, an exception to the rule, when we have clear evidence that there is a nuclear weapon being built,” Gavouneli told Al Jazeera.
Israel might try to make the case that its “continued existence was at stake and they had to act”, she said. To make this case, Israel would need “warranties, some kind of evidence offered by the International Atomic Energy Agency”, the UN’s nuclear watchdog.
