analysis

The US has attacked nuclear facilities in Iran. Experts say this is hardly justifiable under international law. An analysis.

The United States has intervened in the war between Israel and Iran and targeted nuclear facilities in Iran. US President Donald Trump, in a text message on his social media service"Truth Social," spoke of "very successful attacks" that night.

Meanwhile, US Secretary of Defense Pete Hegseth has also praised the attacks as an"overwhelming success." However, international law fundamentally obliges states to engage in peaceful relations with one another. The legal basis for this can be found in the Charter of the United Nations (UN).

Prohibition of the use of force under international law

This prohibits the use of force under international law. Article 2 states:

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 other manner inconsistent with the Purposes of the United Nations.

This means that UN members are not allowed to simply attack other UN members militarily. There is only one exception to this prohibition on the use of force: the right of self-defense.

UN Charter allows self-defense

This is also explicitly mentioned in the UN Charter. Article 51 states:

Nothing in this Charter shall impair the inherent right of individual or collective self-defence in the event of an armed attack against a Member of the United Nations.

A state may therefore use military means if it is itself attacked. Legitimate defensive actions then include strikes against military targets on the territory of the attacking state.

Tight limits for"preemptive self-defense"

A state may defend itself against an imminent attack, provided no other means are available. International lawyers call this"preemptive self-defense," Professor Pierre Thielbörger of the Bochum Institute for Peacekeeping Law and International Humanitarian Law told the ARD legal department last week.

"However, 'preventive self-defense' against a merely possible future attack that is not yet imminent is inadmissible," said the international law expert.

No evidence of an attack planned by Iran

The crucial question in determining whether a state may invoke its own right of self-defense is: Was an attack imminent? And how concrete was the threat?

In the case of the US attacks on Iran, it would have to be examined whether Iran was imminently about to attack the US. However, as far as we can see, there is currently no reliable evidence for this.

Against this backdrop, international law expert Jochen von Bernstorff described the US attacks today to the dpa news agency as"clearly illegal." He said: "I see little scope for justification under international law."

Support for Israel's self-defense?

Article 51 of the UN Charter speaks not only of the "individual" but also of the "collective" right of self-defense. This means that it is entirely compatible with international law to provide military support to another state in its self-defense against an attack.

However, this requires that the other state is in a position of self-defense. That is, if one were to interpret the US attacks as legitimate support for Israel, this would only be possible if Israel itself could invoke the right of self-defense against Iran.

International lawyers skeptical

However, the majority of international lawyers in Germany did not and do not see Israel as having a right to self-defense against Iran – neither when Israel began shelling on June 13 nor currently.

For example, former Federal Constitutional Court judge Andreas Paulus said in an interview with Legal Tribune Online (LTO):"The explicit, latent threat to Israel from the mullah regime is to be taken seriously, but is not sufficient on its own for permissible self-defense."

International law expert Pierre Thielbörger assessed the situation similarly: "With Israel's attacks, we are still operating in the area of preventive self-defense, which international law does not recognize in order not to undermine the actually applicable prohibition of the use of force between states," he told the ARD legal department.

Nuclear facilities under attack

In its attacks, the US has targeted Iranian nuclear facilities exclusively. Even if military strikes are – exceptionally – permissible under international law, such facilities still enjoy special protection.

The Additional Protocol to the Geneva Conventions, adopted in 1977, stipulates that nuclear power plants may not be attacked even if they are military objectives,"provided that such an attack may release dangerous forces and thereby cause heavy casualties among the civilian population."

Special protection of nuclear power plants

An exception to this ban is only possible under very strict conditions. Namely, if a nuclear power plant"provides electrical power in regular, significant, and direct support of hostilities, and if such an attack is the only practically possible means of terminating such support."

This category includes facilities used for uranium enrichment for military purposes, said international law professor Christoph Safferling of the University of Erlangen-Nuremberg in an interview with the Süddeutsche Zeitung.

"Then, under international law, it would be considered an arms factory, thus a legitimate target in war." However, the prerequisite would remain that military strikes would be justified in the specific situation, i.e., that a situation of permissible self-defense exists.