Military spending

Post 9/11 wars have cost American taxpayers $6.4 trillion, study finds

American taxpayers have spent some $6.4 trillion in nearly two decades of post-9/11 wars, which have killed some 800,000 people worldwide, the Cost of Wars Project announced Wednesday.

The numbers reflect the toll of American combat and other military operations across some 80 nations since al-Qaida operatives attacked the World Trade Center in New York and the Pentagon in Washington in 2001, launching the United States into its longest-ever wars aimed at stamping out terrorism worldwide.

The annual spending estimates released Wednesday show a general decline in war costs in 2019 as U.S. troops face less combat in major war zones such as Afghanistan, Iraq and Syria. Still, the estimated price tag for those wars increased some $500 billion since November 2018, and it has doubled since the Cost of Wars Project — a product of Brown University’s Watson Institute of International and Public Affairs and Boston University’s Frederick S. Pardee Center — first looked at cumulative wartime costs in 2011.