At 8:46 a.m. on Sept. 11, 2001, American Airlines Flight 11 barrelled into the North Tower of the World Trade Center, instantly taking hundreds of lives and turning the heads of New Yorkers up to a smoke-filled sky.
In the next hour and 45 minutes, another jetliner would slam into the South Tower, both iconic columns would collapse, a plane would strike the Pentagon and another would crash in a field near Shanksville, Pennsylvania.
By the end of the day, nearly 3,000 people had died. Toxins swirling among the wreckage would be linked to the deaths of as many as 100 first responders who rushed to the scene to help.
The American public didn’t know it then, but the attacks would also launch what the Bush administration dubbed the “war on terror,” decades-long military conflicts that would make the death toll on 9/11 seem small in comparison.
While it’s impossible to know just how many people died in the post-9/11 military operations, which reached across the Middle East to Iraq, Afghanistan, Syria and elsewhere, scholars at the Costs of War Project at Brown University’s Watson Institute for International and Public Affairs have been working on estimates since 2010. They put the human toll at more than 890,000, including armed forces on all sides of the conflicts, contractors, civilians, journalists and humanitarian workers.
The project took into account data from a range of sources, including the Department of Defense, the United Nations, national governments in Iraq and Afghanistan and journalist’s accounts – all of which often came to different conclusions.
Here’s a snapshot of their findings, however imperfect:
Civilian Deaths: 363,939 – 387,072
Of all those who died in the post-9/11 wars, civilians accounted for the largest share by far. The Costs of War Project estimates that more than 360,000 civilians lost their lives at the hands of opposition fighters, local militaries and U.S. and coalition forces. Not counted in those numbers are journalists (680) and workers at nongovernmental organizations (892).
Figures like 387,072 dead may seem strangely precise, admits Costs of War co-Director Neta C. Crawford. Ultimately, she says, “nobody knows” exactly how many civilians have died. That’s partly because “politics has hindered the level of accuracy.” Government and opposition forces often have incentives to exaggerate civilian deaths, for example, and the U.S. tends to have a more narrow definition of “civilian” than groups like the United Nations.
Most civilian deaths took place in Iraq, where as many as 208,000 people perished. Syria saw the second-highest death toll, with 95,000 casualties. Both countries were harder hit than Afghanistan – where about 46,000 civilians died – because of their higher population density, Crawford says.
While those numbers may sound staggering, experts point out they are far lower than the civilian death toll in the Vietnam War, in which as many as 2 million noncombatants died.
And while U.S. forces were certainly responsible for some civilian deaths, Crawford notes that the level of care the military showed in averting civilian casualties was “unprecedented in the history of U.S. war.”
“The United States has taken great care to avoid harming civilians, especially with drone strikes,” she says.
Part of that may have had to do with outside pressure. In some instances, she says, the U.S. military actually restricted air strikes in response to media and international organizations reporting civilian losses.
“It seems like it makes a difference whether or not we the people are paying attention,” she says.
Despite the U.S. withdrawal from Afghanistan last month and the country’s plan to remove combat troops from Iraq by the end of the year, experts don’t expect civilian deaths to stop anytime soon. Civilians could become collateral damage as local forces continue to fight, for example, and the U.S. could still inadvertently inflict casualties from the air.
“If the U.S. continues to conduct airstrikes, whether through drones or through directly piloted aircraft in places like Iraq, Afghanistan and Somalia, then we’re likely to keep seeing civilian casualties,” says Daphne Eviatar, director of security with human rights at Amnesty International.
Crawford also notes that there will continue to be “indirect” civilian deaths from the wars. Those deaths, though not counted in her tallies, are often the result of factors like destroyed infrastructure, famine and displacement – scenarios reminiscent of what’s playing out now in Afghanistan.
“There’s one category of direct deaths that is killing people due to bombs, fire, shrapnel, walls falling on them when there’s a blast,” Crawford says. “Those are direct deaths. Indirect deaths are by far the larger killer.”
U.S. Military Deaths: 7,052
About 7,000 U.S. service members have died in the post-9/11 conflicts to date, according to Costs of War. That total includes 2,324 military personnel who died from 2001 to 2021 in Afghanistan – America’s longest war – and 4,598 who died in Iraq during two phases: the 2003 to 2011 operation, which started as an effort to oust then-leader Saddam Hussein and disarm the country of weapons of mass destruction, and from 2014 to the present, in which the U.S. is battling the Islamic State group.
While any number of military casualties strike a blow to the American public, Deborah Avant, director of the Sié Chéou-Kang Center for International Security at the University of Denver, points out that historically speaking, the overall number of military casualties in these conflicts is relatively low.
“One of the things that people don’t think about because they are focused right now on how horrific this was – and the last few weeks have been tough – is that there were far fewer [military] people who died in these wars than who died in Vietnam,” she says.
Indeed, about 58,000 service members died as a result of the Vietnam war from 1964 to 1975, according to the National Archives. More than 36,000 died in the Korean War, and more than 400,000 died during World War II.
The main reason for the smaller casualty figures is a “tremendous improvement in battlefield medicine,” says Crawford. Even when improvised explosive devices caused grave wounds, service members were often quickly airlifted to hospitals where their lives were saved, even if their limbs were not.
Lingering disabilities represent another facet of the human toll of the post-9/11 conflicts: Veterans of today’s wars are far more likely than their predecessors to have serious injuries such as second- and third-degree burns, brain injuries, spinal cord injuries, nerve damage, post-traumatic stress disorder and limb loss.
They are also far more likely to have experienced multiple deployments, which increased the risk of traumatic physical and psychological exposure.
“People don’t necessarily know about the mental trauma that goes along with such a long war,” says Stephanie Savell, another co-Director of the Costs of War Project. She points to research showing that an estimated 30,177 active-duty personnel and war veterans of post-9/11 conflicts have died by suicide – four times as many as those who died in combat.
U.S. forces, of course, weren’t the only military personnel who participated in post-9/11 operations. Among other allied troops, Costs of War estimates 14,874 died in the conflicts. The group also estimates that between 204,645 to 207,845 national military police lost their lives, as well as 296,858 to 301,933 opposition fighters.
U.S. Contractor Deaths: 8,189
Of the U.S. citizens serving in the Middle East post-9/11, contractors bore the brunt of the casualties – even more so than members of the U.S. military.
That’s partly a result of their sheer numbers. By 2011, more private contract employees were on the ground in Iraq and Afghanistan than U.S. service members. They were assisting in various ways, providing everything from food to transportation to lodging.
While the U.S. had used contractors during the Balkan wars, where they were working in a more “forgiving context,” taking on jobs that were less likely to put them in danger, says Avant with the University of Denver. But when contractors flooded into Iraq and Afghanistan in the early stages of the conflicts, “nobody had really thought through what it would mean to have them in harm’s way to the extent that they were in those wars,” she says.
By the time U.S. contractors began to have more regulations surrounding protections – around 2008 – many of their employees had already fallen victims to the war.
The U.S. government employed more international than U.S. contractors during the conflicts. Among the American contractors who died, Crawford estimates 3,917 perished in Afghanistan, 90 perished in Pakistan, 3,650 died in Iraq and 19 lost their lives in Syria. However, due to the challenges tracking contractor deaths, she believes the actual figures are higher.
Scholars at the Costs of War note the challenging nature of cataloguing with any precision the thousands of deaths that have occured over the last 20 years but say the effort to keep the government – and the public – informed and accountable justifies the work.
“Our work pushes people to ask questions that they don’t normally ask about war in general and the post-9/11 wars in particular, like, ‘Is it worth it? Is the U.S. meeting its goals, protecting Americans and protecting others around the world?'” Savell says. “And if it’s not, then we should be thinking about how to take a different approach.”