As the US and Israel began their joint assault on Iran, reports emerged from Iran that a strike hit the Shajarah Tayyebeh girls’ elementary school in the southern city of Minab.

The school was reportedly packed with young pupils at the time. Iranian authorities say more than 150 people were killed, including children, and 60 more injured (these figures are yet to be independently verified).

Videos verified by international media show rescue workers digging through collapsed concrete, school bags being pulled from the debris, and scorch marks along the remaining walls.

Warning: this gallery contains graphic images.

The New York Times says it has verified videos that show the school next to a naval base belonging to the Iranian Revolutionary Guards Corps, or IRGC, and a strike hitting that base.

Iranian representatives at the United Nations have characterised the strike as a deliberate targeting of civilian infrastructure and labelled it a war crime and a crime against humanity.

Neither the United States nor Israel have publicly confirmed hitting the school. The US military’s Central Command (Centcom) said:

We are aware of reports concerning civilian harm resulting from ongoing military operations. We take these reports seriously and are looking into them. The protection of civilians is of utmost importance, and we will continue to take all precautions available to minimize the risk of unintended harm.

At present, we do not have enough verified facts to reach a firm legal conclusion about what happened.

But given the questions about the legality of the US and Israeli strikes on Iran – and deeper questions about whether we’re witnessing the “death of international law” more broadly – incidents like this illustrate the continuing importance of the law, especially in times of conflict.

Which targets are protected under the law?

In armed conflict, international humanitarian law applies. International humanitarian law is built on foundational principles that must inform all decisions by armed forces concerning what they target:

• distinction

• proportionality

• military necessity

And precautions must be taken to avoid incidental harm to civilians.

So what do these terms mean?

The principle of distinction requires parties to an armed conflict to always distinguish between civilian objects and military objects.

Attacks may only be directed against combatants and military objects. Civilians and civilian objects, such as schools, hospitals and public transport, are protected and may not be directly targeted.

If there is any doubt about whether a target is military or civilian in nature, it must be presumed to be civilian.

Schools are not merely buildings. They are protective spaces, and their destruction can cause immediate loss of life and long-term societal damage.

Children under 18 also enjoy special protection under international humanitarian law. They, too, may not be directly targeted.

This protection is not absolute, however. Any civilian object (including schools) can lose their protected status if they become military objectives. A school used as a military base, artillery position or command post could meet that definition.

So far, we have no evidence the school in Minab was being used for military purposes or that it was intentionally targeted.

Proportionality and precautions in attacks

What, then, if the school was not intentionally targeted, but was incidental collateral damage from an attack directed at the IRGC barracks nearby?

International humanitarian law recognises civilian objects may be affected by attacks on military objectives.

Incidental harm to civilians and civilian objects is only lawful if it satisfies the test of proportionality and military necessity under the law. All feasible precautions must also have been taken to minimise harm to civilians.

So, if a school near a military target is hit, the legality of that strike turns on whether the expected harm to children and the school was excessive compared to the military advantage gained by striking the target.

Also important: did the military commanders take all feasible precautions to assess the effect of the attack on nearby civilians or civilian infrastructure? This includes the specific weapons that are used and the timing of the attack.

Why international law matters

In recent years, we have witnessed a number of countries and their leaders openly flouting international law and the rules-based order. Yet, it would be a profound mistake to conclude that international law has ceased to matter. Even grave breaches do not negate the system itself.

As renowned American international law scholar Louis Henkin famously wrote in 1979:

Almost all nations observe almost all principles of international law and almost all of their obligations almost all of the time.

Henkin’s point was not naïve optimism. Daily compliance of international law remains the norm in diplomacy, trade, aviation, maritime navigation, treaty compliance and peaceful dispute settlement.

Violations do occur – sometimes brazenly – but they are exceptions to an overwhelmingly compliant pattern of behaviour.

The fact that some states breach foundational rules such as the prohibition on the use of force in Article 2(4) of the United Nations Charter does not render international law illusory.

Rather, it underscores the importance of naming breaches for what they are and defending the legal order that most states, most of the time, continue to respect.

If the strike on the Minab school is ultimately shown to have violated the principles of distinction, proportionality and military necessity, it would not prove Henkin wrong; it would prove his point.

International law matters precisely because departures from it can be identified, judged and condemned.

The rubble of a girls’ school is not evidence that the law is meaningless; it is a stark reminder of why the law exists, and why insisting on compliance remains essential.

Shannon Bosch does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.