The United States has spent about $21 trillion on military operations since the 2001 attacks in the country, according to a study conducted by the Institute for Policy Studies.

Nearly 75% of this amount, which totals to about $16 trillion, was spent on operations related to the Pentagon, nuclear programmes, intelligence, defense aid and requirement benefits, according to reports from Newsweek citing the study conducted by the Washington-based institute. 

Other expenditures out of the $21 trillion were sent towards federal law enforcement ($732 billion), Homeland Security ($949 billion) and Veterans programmes ($3 trillion).

The study also suggested other sectors of the United States where the amount could have been invested. Newsweek reported these sectors to be:

1) $4.5 trillion could fully decarbonize the United States electric grid

2) $2.3 trillion could create 5 million $15 per hour jobs with benefits and cost-of-living adjustments for 10 years

3) $1.7 trillion could erase student debt

4) $449 billion could continue the extended Child Tax Credit for another 10 years

5) $200 billion could guarantee free preschool for every 3-and-4-year old for 10 years, and raise teacher pay

Brown University also conducted a similar study called ‘Costs of War Project’ that estimated the loss of life around the world related to the 9/11 incident. The study included data from countries like Iraq, Afghanistan, Yemen, Pakistan and Syria.

The estimate of the study conducted by Brown University determined the fatality toll of the conflicts triggered after the 9/11 attacks to be between 897,000 to 929,000, according to reports from Newsweek.

The death toll included journalists, civilians, soldiers, aid workers, rebels and others.

“Several times as many more have been killed as a reverberating effect of the wars — because, for example, of water loss, sewage and other infrastructural issues, and war-related disease”, the study said, according to reports from Newsweek.