If the financial costs are elusive, so too is the human toll.
The report estimates between 224,475 and 257,655 have been killed in Iraq, Afghanistan and Pakistan, though those numbers give a false sense of precision. There are many sources of data on civilian deaths, most with different results.
The civilian death toll in Iraq — 125,000 — and the number of Saddam’s security forces killed in invasion — 10,000 — are loose estimates. The U.S. military does not publish a thorough accounting.
“We don’t do body counts,” Tommy Franks, the U.S. commander in Iraq, famously said after the fall of Saddam in 2003.
In Afghanistan, the civilian death count ranges from 11,700 to 13,900. For Pakistan, where there is little access to the battlefield and the United States fights mostly through aerial drone attacks, the study found it impossible to distinguish between civilian and insurgent deaths.
The numbers only consider direct deaths — people killed by bombs or bullets. Estimates for indirect deaths in war vary so much that researchers considered them too arbitrary to report.
“When the fighting stops, the indirect dying continues. It’s in fact worse than land mines. The healthcare system is still in bad shape. People are still suffering the effects of malnutrition and so on,” Crawford said.
Even where the United States does do body counts — for the members of the military — the numbers may come up short of reality, said Lutz, the study’s co-director. When veterans return home, they are more likely to die in suicides and automobile accidents.
“The rate of chaotic behavior,” she said, “is high.” (Additional reporting by Susan Cornwell, Missy Ryan, Brett Gering, Laura MacInnis and Sharon Reich; Editing by Doina Chiacu)