After the 9/11 attacks, the US will have spent $5.8tn waging war in Afghanistan, Iraq, Pakistan and Syria by the end of 2022, according to updated
figures from the Costs of War Project at Brown University.
The figure - which includes interest on debt used to finance the wars - will continue to increase in the decades ahead, with healthcare for veterans projected to hit $2.2tn by 2050.
The wars in Afghanistan and Iraq differ from previous wars as they were mostly funded by borrowing, rather than through taxes and war bonds.
"It's critical we properly account for the vast and varied consequences of the many US wars and counterterror operations since 9/11, as we pause and reflect on all of the lives lost," Neta Crawford, a co-director of the Costs of War Project and chair of the political science department at Boston University,
told CBS News.