US, Israel Spend $3.7bn in First 100 Hours of War on Iran
US–Israeli campaign cost
CSIS estimates place the combined US–Israeli campaign’s cost at about $3.7 billion in its first 100 hours, roughly $891.4 million per day, with the bill driven by heavy munitions use and strikes involving stealth bombers and advanced systems.
“The United States-Israeli war on Iran is estimated to have cost Washington $3”
Analysts Mark Cancian and Chris Park emphasise the rapid, high-intensity opening phase as the principal cost driver.
Cost and munitions summary
The CSIS analysis provides a detailed cost breakdown.
Roughly $196 million is accounted for operational costs, most of which had been earmarked.
About $3.1 billion is listed to replace expended munitions.
Another roughly $350 million is allocated to replace combat losses and repair infrastructure.
These figures underline how materially intensive the opening strikes were.
The report also notes US forces fired more than 2,000 munitions in that initial phase.
CSIS spending estimate
A striking feature of the CSIS estimate is how much of the initial spending was unbudgeted: roughly $3.5 billion of the $3.7 billion total.
“The United States’ military campaign against Iran has cost an estimated $3”
CSIS authors warn that these unplanned expenses mean the Pentagon will likely need supplemental appropriations from Congress, a politically sensitive step that the analysis says could become a focal point for opposition to the administration.
Replenishment needs and costs
Beyond the first 100 hours, CSIS and reporting note larger replenishment requirements and limited public detail from the Pentagon.
Analysts say the Department of Defense has prepared a possible $50 billion supplemental request to replenish Tomahawk and Patriot missiles, THAAD interceptors and other expended or worn equipment, while the Pentagon has released only limited operational details to date.
The CSIS estimate also excludes Israeli costs.
Funding tied to campaign intensity
The CSIS report and multiple outlets stress that future spending will hinge on operational intensity and the level of Iranian retaliation.
“The United States-Israeli war on Iran is estimated to have cost Washington $3”
Costs could fall if US forces shift to cheaper munitions and Iranian strikes decline, but could rise if operations expand.
Defense Secretary Pete Hegseth signalled the campaign may grow, saying bombardment is "about to surge dramatically."
Some outlets place the start of the campaign at Feb. 28, and CSIS says these factors will determine whether further supplemental funding is required.
Key Takeaways
- United States spending on the war reached $3.7 billion in the first 100 hours
- Average expenditure totaled about $891.4 million per day during those 100 hours
- Approximately $3.5 billion of the spending was not previously budgeted
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