US Soldiers OIR aerial extraction Iraq 1st Lt. Leland White/US Army National Guard

Federal spending on post-9/11 military action in Iraq and Afghanistan stands at $6.4 trillion through fiscal year 2020, according to a new study from the Cost of War project at Brown University.

Its cost to American taxpayers will keep climbing for decades to come.

The staggering amount reflects spending across the federal government and not just the Department of Defense, the study noted.

The report said the US government should expect to spend at least $1 trillion in benefit payments and disability claims for veterans in the years to come.

Back in March, the Department of Defense estimated that the wars in Iraq, Afghanistan, and Syria have cost each US taxpayer around $7,623 to date.

Visit Business Insider’s homepage for more stories.

Federal spending on post-9/11 military action in Iraq, Afghanistan, and elsewhere around the world stands at $6.5 trillion through fiscal year 2020, according to a new study from the Cost of War project at Brown University.

And its cost to American taxpayers will keep climbing for decades to come.

The staggering amount reflects spending across the federal government and not just the Department of Defense, the study noted. Much of it has been paid for deficit spending as taxes were not raise to cover the cost.

The study said military action taken after the 9/11 attacks has now expanded to more than 80 countries, making it „a truly global war on terror.“

Its human costs have been profound as well. Over 801,000 people died as a direct result of the fighting — 335,000 of them being civilians, according to the report.

The report said the US government should expect to spend at least $1 trillion in benefit payments and disability claims for veterans in the next several decades. Last year, there were 4.1 million post 9/11 war veterans, making up around 16% of all veterans served by the Department of Veterans Affairs.

„Even if the United States withdraws completely from the major war zones by the end of FY2020 and halts its other Global War on Terror operations, in the Philippines and Africa for example, the total budgetary burden of the post-9/11 wars will continue to rise as the U.S. pays the on-going costs of veterans‘ care and for interest on borrowing to pay for the wars,“ study author Neta Crawford wrote.

Back in March, the Department of Defense estimated that the wars in Iraq, Afghanistan, and Syria have cost each US taxpayer around $7,623 to date.

Open-ended military operations overseas have stretched on for so long that starting on Sept. 11 last year, an 18-year-old person could enlist in the military and fight in the wars that the 9/11 attacks ushered in.

The estimate drew attention from one of the leading Democratic presidential candidates: Sen. Bernie Sanders, who quipped on Twitter about its colossal price tag on Thursday. The Vermont senator had previously slammed „costly blunders“ made in US foreign policy over the years.

Tweet Embed:

//twitter.com/mims/statuses/1197281716395601921?ref_src=twsrc%5Etfw

How are you going to pay for that? https://t.co/gkUeAa2XXI

Moderate rivals had criticized Sanders for the sweeping costs of his progressive agenda, which include implementing a universal healthcare system, forgiving all student debt, and tackling climate change through the Green New Deal.

Several Democratic candidates, including Sanders, Mayor Pete Buttigieg (an Afghanistan war veteran) and Sen. Elizabeth Warren, have vowed to wind down US military operations overseas. Others like former vice president Joe Biden say some nations would continue requiring American military support.