The Costs of War project conducts and publishes research about the ongoing consequences of the United States post-9/11 wars in Afghanistan, Iraq and elsewhere; the costs of global U.S. military operations; and the domestic effects of U.S. military spending. Created in 2010 and housed at Brown University’s Thomas J. Watson Jr. School of International and Public Affairs, the Costs of War project builds on the work of over 70 scholars, experts, human rights advocates, and physicians from around the world.
Recent Findings
In the two years since the October 7, 2023 Hamas attack on Israel, the U.S. government has spent $21.7 billion on military aid to Israel.
The U.S. has spent an additional $9.65 – $12.07 billion on military operations in Yemen and the wider region since October 7, 2023, for a total of $31.35 – $33.77 billion and counting in U.S. spending on the post-10/7 wars.
As of October 3, 2025, 67,075 people in Gaza have been killed and 169,430 people injured according to the Gaza Ministry of Health. These 236,505 casualties constitute more than 10% of the pre-war population in Gaza.
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United States Post-9/11 Wars
The U.S. government is conducting counterterror activities in 78 countries.
An estimated 3.6-3.8 million people have died indirectly in post-9/11 war zones, bringing the total death toll to at least 4.5-4.7 million and counting.
At least 940,000 people have died due to direct war violence, including civilians, armed forces on all sides, contractors, journalists, and humanitarian workers.
U.S. policymakers scarcely considered alternatives to war in the aftermath of 9/11 or in debating the invasion of Iraq. Many of those alternatives are still available.
The cost of the post-9/11 wars in Iraq, Afghanistan, Pakistan, Syria, and elsewhere totals about $8 trillion. This does not include future interest costs on borrowing for the wars.
38 million people have been displaced by the post-9/11 wars in Afghanistan, Pakistan, Iraq, Syria, Libya, Yemen, Somalia, and the Philippines.
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