Mosul al-Jadida Airstrike: US Bomb Collapses Building on Sheltering Families, Killing At Least 105 Civilians (March 2017)

What Happened

By March 2017 Iraqi forces, backed by US-led coalition air power, were fighting the Islamic State (ISIS) street by street in west Mosul. Amnesty International reported that residents had received "repeated instructions from the Iraqi government to remain in their homes" during the offensive: "We heard these instructions on the radio… Also leaflets were dropped by planes," one resident said.

On 17 March 2017 a US aircraft dropped a GBU-38 precision-guided bomb on a large building in the al-Jadida neighbourhood of west Mosul. Its target, according to the US military's investigation, was two ISIS snipers firing from the second storey. The building collapsed. The investigation, presented by Brig. Gen. Matt Isler and reported on 26 May 2017, found that 101 civilians sheltering in the lower floors and four in the neighbouring structure were killed, at least 105 in all, and that 36 more were unaccounted for (Middle East Eye).

The investigation concluded that the bomb alone could not have brought down the building. Central Command said: "Post-blast analysis detected residues common to explosives used by ISIS, but not consistent with the explosive content of a GBU-38 munition." It attributed the collapse to "a large amount of explosive material which IS militants had previously placed inside." Isler said Iraqi counter-terrorism forces and the coalition "did not know civilians were in the building" (Middle East Eye).

Amnesty International, reporting from Mosul on 28 March 2017, said up to 150 people were reported killed in the al-Jadida strike. It described an "alarming pattern of US-led coalition airstrikes" destroying homes with families inside in east and west Mosul (Amnesty).

Legal Analysis

Armed conflict. The fighting between Iraqi forces, supported by the coalition, and ISIS was a non-international armed conflict. The customary rules on distinction, proportionality and precautions in attack apply to US forces.

Was the target lawful? Two snipers actively firing are a lawful military objective. The question is not the target but the attack: whether those planning it did everything feasible to verify who else was in the building, and whether the expected civilian harm was excessive compared with the military advantage of killing two snipers.

Precautions (contested, credibly alleged). Amnesty concluded that the coalition had failed "to take adequate precautions to prevent civilian deaths, in flagrant violation of international humanitarian law". The government's instruction to residents to stay at home made it foreseeable that buildings in contested neighbourhoods would be full of civilians, and Amnesty documented a pattern of strikes on occupied homes. Against that, the US investigation found the civilians' presence was not known.

Proportionality (not shown). A war crime under Article 8(2)(b)(iv) applies only in international armed conflict, and the Rome Statute has no equivalent for non-international conflicts, though a customary war crime of disproportionate attack in such conflicts is widely accepted. Either way, the attacker must have known that the attack would cause clearly excessive civilian harm. If the US did not know about the people inside and did not expect the building to collapse, that knowledge is missing. Only an investigation with access to the surveillance and targeting record could establish otherwise.

Strongest defence argument. The US used a relatively small precision bomb against a specific threat. It says the catastrophic outcome came from ISIS explosives it could not have known about, and that it was unaware of the civilians. If accurate, that defeats the mental element of any war crime. The defence is weakened, but not defeated, by the government's stay-at-home instruction, which made a full building foreseeable, and by the fact that the investigation was conducted by the attacking force itself.

Jurisdiction. Neither Iraq nor the US is an ICC State Party.

Why This Grade

This entry is graded severe with a war-crime classification of potential.

• The harm is concrete and acknowledged: at least 105 civilians killed by the attacking state's own count in a single strike.
• Amnesty applied international humanitarian law to the facts and found a failure of precautions. That supports a reasonable basis to suspect a war crime, the "potential" threshold.
• The decisive element, knowledge that civilians were inside or that the harm would be excessive, has not been shown to the reasonable-grounds standard. The only investigation, by the US itself, found the opposite. It therefore does not meet the extreme grade.

Confidence in this grade: medium.