Estimation of the Costs of U.S. Military Operations in the Middle East: War Expenditures and Regional Impact

Key Chapter Title List

1. Abstract
2. Operations Against the Houthis in the Broader Region
3. U.S. Presence in the Broader Middle East and the Context of Its Actions in Yemen
4. Costs of U.S. Engagement and Operations Against the Houthis (From October 1, 2024, to Present)
5. Houthi Actions and Costs Since Operation Rough Rider
6. Long-Term Costs of U.S. Actions Against the Houthis
7. Operation Midnight Sledgehammer (Iran)
8. Context of U.S.-Iran Relations
9. Cost Drivers of Operation Midnight Sledgehammer
10. Cost-Benefit Analysis
11. Broader Regional Linkages with Saudi Arabia
12. Conclusion

Document Introduction

This report is authored by Dr. Linda J. Bilmes of the Harvard Kennedy School and is affiliated with the Costs of War Project at the Watson Institute for International and Public Affairs, Brown University. The report aims to provide a detailed cost estimate for a series of U.S. military operations conducted in the broader Middle East since October 7, 2023, in support of U.S., Israeli, and allied interests. The study covers the period up to September 2025, with the core objective of quantifying the direct financial expenditures of these operations to provide a fact-based budgetary framework for policy discussions.

The report's core estimate indicates that over the two-year period from October 2023 to September 2025, the direct cost of U.S. military operations in the Middle East (primarily targeting the Houthis in Yemen and Iranian nuclear facilities) is estimated to be between $9.65 billion and $12.07 billion. Furthermore, according to a companion report by William D. Hartung, U.S. military aid to Israel during the same period amounts to $21.7 billion. Combined, the total U.S. expenditure related to conflicts in the region during this period ranges from $31.35 billion to $33.77 billion. By comparing with previous estimates released in October 2024, the report reveals a significant increase in spending during the 2025 fiscal year, primarily due to the escalation of military operations.

In terms of analytical methodology, the report strictly relies on available public data, government statements, military analysis reports, and authoritative media coverage to break down the costs of major operations item by item. For the primary operations of the 2025 fiscal year—Operation Rough Rider (the bombing campaign against the Houthis) and Operation Midnight Sledgehammer (the strikes against Iranian nuclear facilities)—the report constructs detailed cost models respectively. Cost components include munition consumption (e.g., Tomahawk cruise missiles, AGM-158 missiles, GBU-57 Massive Ordnance Penetrators), deployment and operation of major assets (e.g., aircraft carrier strike groups, B-2 stealth bombers), logistical transfers (e.g., cross-theater movement of Patriot air defense systems), asset attrition (e.g., lost F/A-18 Super Hornet aircraft), and extensive use of missile defense systems (e.g., Patriot and THAAD interceptor missiles). The report clearly distinguishes between low and high estimate ranges to reflect data uncertainty and notes that indirect costs difficult to quantify, such as diplomatic efforts, administrative costs, and soft power impacts, are not included.

Important findings of the report reveal cost asymmetries and questions regarding strategic effectiveness in U.S. military operations. In the Yemen theater, the U.S. used advanced missiles costing millions of dollars each to intercept Houthi drones costing only thousands of dollars, highlighting cost-effectiveness challenges. Despite the large scale of Operation Rough Rider, it failed to durably curb Houthi attacks on international shipping, and its effectiveness in achieving the strategic goal of significantly degrading Houthi capabilities is questioned by experts. In the Iran theater, Operation Midnight Sledgehammer employed the Massive Ordnance Penetrator, which took 15 years to develop, and B-2 bombers, causing severe damage to Iranian nuclear facilities. However, a U.S. Defense Intelligence Agency assessment concluded it only set back Iran's nuclear program by several months. The operation also consumed approximately one-quarter of the U.S. THAAD interceptor inventory, exposing a potential gap in high-end defensive munition stockpiles.

Finally, the report examines direct military costs within the broader context of regional strategy and long-term burdens. It points out that the massive U.S.-Saudi Arabia defense cooperation agreement may stimulate a regional arms race and pose long-term risks. More importantly, the report emphasizes that current direct war expenditures are merely the tip of the iceberg; the future reconstruction of the Gaza Strip is estimated to require at least $53 billion, with the U.S. likely to bear most of that cost. The report's conclusion reiterates that the American public has a right to understand how funds are used in conflicts and that when evaluating military actions, their enormous financial costs should be weighed against the effectiveness in achieving the goal of promoting regional peace.