Though actual numbers can never be known, the Costs of War Project estimates over 940,000 people died directly as a result of violence due to American foreign policy in the post-9/11 wars in Afghanistan, Pakistan, Iraq, Syria, and Yemen. An additional 3.6–3.8 million died indirectly due to factors like malnutrition, disease, and the breakdown of healthcare systems related to these conflicts. The total death toll, including both direct and indirect casualties, is estimated to be between 4.5 and 4.7 million. The Costs of War Project also highlights the significant displacement caused by these conflicts, with an estimated 38 million people displaced since 2001. Some 7,000 U.S. military service members died. The Project estimates the wars cost the U.S. over $8 trillion. Afghanistan today is again ruled by the Taliban, Iraq by Iranian proxies. Nation-building was a complete failure. The broader neoconservative interventionist policy failed.

https://watson.brown.edu/costsofwar/