The Costs of War Project at Brown University's Watson Center says the figure -- which covers the conflicts in Iraq, Syria, Afghanistan, and Pakistan from 2001 through 2018 -- is the equivalent of more than $23,386 per taxpayer.
The "new report," said Paul Kawika Martin, Peace Action's senior director for policy and political affairs, "once again shows that the true #costofwar represents a colossal burden to taxpayers on top of the tremendous human loss."
The center's figure is far greater than the $1.5 trillion the Pentagon estimated (pdf) in July for the costs of the wars in Afghanistan, Iraq, and Syria, as it gives a fuller picture by including "war-related spending by the State Department, the Department of Veterans Affairs, and Homeland Security," writes Neta C. Crawford, a professor of political science at Boston University.
Her report notes that even the $5.6 trillion tally underestimates the true figures, as it doesn't capture "every budgetary expense related to these wars," such as state and local costs to take care of veterans; nor does it take into account the funds used for military equipment "gifts" to countries involved in the conflicts.
"In sum," it states, "although this report's accounting is comprehensive, there are still billions of dollars not included in its estimate."
In addition, as the Washington, D.C.-based organization Win Without War notes, "let's not forget that when we talk about what war costs there are also human costs. As obscene as it is to waste so much money, it is more obscene to waste human life."