A MERICA HAS conducted 108 air strikes in Somalia since 2017, killing some 800 people. The Pentagon says they were all jihadists. Amnesty International, a human rights organisation, disagrees. It has gathered detailed evidence suggesting that five recent strikes alone killed 14 civilians. That discrepancy between the civilians that external observers say have been killed in American air strikes and the number the government owns up to is repeated across the world.

Donald Trump came to office pledging to wind down America’s wars. Instead, he ramped some of them up. The campaign in Somalia against al-Shabab, a brutal jihadist group which is aligned to al-Qaeda and controls a quarter of the country, saw the number of air strikes trebled from 14 in 2016 to 45 last year. There were 28 in the first three months of 2019 alone.

In part, that may reflect looser rules. Barack Obama had decreed that commanders in places like Somalia and Pakistan—outside of formal war zones like Iraq—required “near certainty” that a target was a high-value terrorist, no civilians would be killed or injured except in “extraordinary circumstances”, and decisions would be informed by inter-agency consultation.

In 2017 Mr Trump overhauled these rules. He not only diluted Mr Obama’s special restrictions on secret wars, but also allowed specific countries to be declared an “area of active hostilities”. In such places, International Humanitarian Law ( IHL )—the more permissive rules that apply in avowed battlefields like Iraq and Afghanistan—would be in force.

In Somalia this meant commanders now needed only “reasonable certainty” that a target was present, and could make their decision without recourse to officials back home. This increased the risk of civilians being misidentified as combatants. Separately, the shift to IHL also meant that commanders could go after foot-soldiers, not just al-Shabab bigwigs.

Disputes over the civilian toll from air campaigns go well beyond Somalia. More American bombs and missiles fell on Afghanistan in 2018 than in any year since published records began a decade ago—more than five times as many as in 2015. Civilian deaths from air strikes correspondingly rose by 87% between 2017 and 2018 to 463, according to Action on Armed Violence ( AOAV ), a monitoring group.

That includes bombs dropped by the Afghan air force, which has far less experience in using precision weapons. But the United Nations Assistance Mission in Afghanistan ( UNAMA ), whose estimates are similar to those of AOAV , says that 62% of aerial casualties—deaths and injuries—were inflicted by the NATO -led coalition, whose air power is largely American. NATO accepts just 62 of those deaths, a small proportion of UNAMA ’s total, though it agrees that another 68 are disputed.

A similar story has played out in the Middle East. By March the American-led coalition battling Islamic State across Iraq and Syria had owned up to at least 1,257 civilian deaths since the start of the war. Airwars, a London-based NGO , says the figure is probably six times higher, over 7,500—an average of one civilian death every four strikes. Airwars is particularly scathing of Britain’s claim to have killed just one civilian among 4,000 or so enemies. Britain, it says, is “seemingly incapable of detecting civilian casualties from its urban actions.”

Fog of law

This uncertainty stems in part from the nature of modern war. On most of its battlefields, small bands of American and allied special forces quietly direct air strikes using laser guidance and other high-tech methods. But America also outsources the job to regional allies, such as Kurdish rebels in Syria and secret paramilitary units made up of Afghans. Many of these local proxies can call in air strikes, but they have neither the inclination nor the expertise to conduct detailed investigations of the aftermath on the ground.

That leaves America reliant on overhead imagery, coupled with what limited human or electronic intelligence may trickle in, to count bodies. This is particularly limiting when it comes to evaluating casualties inside buildings in built-up areas. In some cases the people on the ground—whether al-Shabab in Somalia or Pakistan’s intelligence agency—deliberately obfuscate matters, keeping the press away from bombed areas. But America’s own rules also appear to be part of the problem.

American commanders evaluate casualty claims made by external organisations in inconsistent and sometimes restrictive ways. One study of Iraq and Syria by Azmat Khan and Anand Gopal for the New York Times in 2017 found that armed forces would entertain allegations only within 50 metres of an air strike, considerably narrower than the blast radius of some American weapons. In other cases they were more reasonable, considering claims within several miles.

American commanders may also be primed to underestimate figures. Larry Lewis, a former official who led seven Pentagon studies on how to avoid civilian casualties in Afghanistan, points out that America’s pre-strike process for estimating collateral damage, though rigorous, “has never been calibrated with real world data to test its accuracy.”

The Pentagon has taken note of all this criticism. In February it partially declassified a study from 2018 of civilian casualties caused over the previous three years. The study insisted that there was a “widespread priority to minimise civilian casualties from the highest to the lowest levels,” but found that the coalition against Islamic State had systematically undercounted.

The report said that 58% of civilian casualties assessed as “credible” came from external allegations, not internal sources. In fact, America’s armed forces often turn to the very same NGO s that hold their feet to the fire on these matters. In 2018 the vast majority of civilian casualty assessments published by the coalition–over 1,000 alleged events–were sourced to Airwars, the NGO based in London.

Airwars now liaises closely with American forces, and both sides swap data on a regular basis. “Progressively over time we’ve seen improvements in our relationship and the standard of their assessments and ours,” says Chris Woods, Airwars’ founder and director.

The Pentagon’s study exhorted officials to build on efforts like these. It urged officials to “systematically seek out additional sources of information on potential civilian casualties,” including social media and NGO s. It proposed that commanders around the world should take on staff to reconcile the Pentagon’s claims with those of others, and standardise their process for making assessments. Its general thrust was to encourage transparency.

Mr Woods says that the Americans have been “pioneering” on addressing civilian harm, “way ahead of Europeans”. That, he suggests, is the result of pressure from legislation and bipartisan interest from Congress. On May 1st the Pentagon is due to publish a congressionally mandated report on global civilian casualties.