SAN FRANCISCO - In the two years since the outbreak of the latest Gaza conflict on Oct 7, 2023, the US government has spent $21.7 billion on military aid to Israel, according to a study findings released Tuesday.

The study, performed by the Costs of War Project at Brown University's Watson Institute for International and Public Affairs, noted that under both the Biden and Trump administrations, agreements with an additional tens of billions of dollars of arms sales have been committed for weapons and related services that will be paid for in the coming years.

US-supplied arms have been central to operations of the Israel Defense Forces (IDF) and Israel Police in Gaza, the West Bank, and beyond. Most of the weapons currently used by Israel in Gaza and across the Middle East come from its existing US-made inventory, according to the study, which was produced in collaboration with the Washington-based Quincy Institute for Responsible Statecraft.

Given the scale of current and future spending, the study suggested, it is clear that the IDF could not have inflicted such extensive damage in Gaza or escalated military activities across the region without US financing, weapons, and political support.

A companion report estimated that the United States has spent an additional $9.65-12.07 billion on military operations in Yemen and the wider region that were either triggered by or conducted in support of Israeli military actions since Oct 7, 2023.

This brings total US spending in the Middle East over the past two years to $31.35-33.77 billion and counting, according to the project.

As of early September 2025, a total of 67,075 people have been killed and 169,430 injured in Gaza, according to the Gaza Ministry of Health. These 236,505 casualties represent more than 10 percent of Gaza's pre-conflict population, the Costs of War Project said.

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At least 5.27 million people have been displaced or forced to flee their homes in Gaza, Iran, Israel, Lebanon, and the West Bank since Oct 7, 2023 - including an estimated 1.85 million children under 18, it added.

From 2020 to 2024, private contractors received $2.4 trillion in contracts from the US Department of Defense, accounting for roughly 54 percent of the Pentagon's discretionary spending of $4.4 trillion, according to the Costs of War Project.