U.S. Has Already Spent $3.7 Billion in Its War Against Iran, Analysts Say

The United States has spent at least $3.7 billion in the first 100 hours of its war against Iran, representing a cost of nearly $900 million per day, according to an analysis by the independent Center for Strategic and International Studies (CSIS).

This is the most comprehensive estimate released to date in the United States regarding the cost of the war launched on Saturday by President Donald Trump and Israeli Prime Minister Benjamin Netanyahu, a conflict that has since spread across the region.

The Washington-based CSIS published its analysis on Thursday examining the financial impact of the first four days of the war, which the center notes "are typically the most intense of an air campaign" — a period that included the airstrikes that killed Supreme Leader Ali Khamenei and much of Iran's senior leadership.

Those first 100 hours cost $891.4 million per day, and the overwhelming majority of those expenditures were unbudgeted: approximately $3.5 billion of the $3.7 billion consumed from Saturday through Tuesday was not included in spending approved by the U.S. Congress, according to the analysis published on the CSIS website.

By contrast, in the case of the Caribbean operations that led to the capture of Venezuelan President Nicolás Maduro in January, most costs were budgeted and amounted to approximately $31 million per day, according to the same analysts.

$1.7 Billion on Air Interceptors, $1.5 Billion on Munitions

The think tank projects that, in the case of Iran, costs will begin to decline as U.S. forces shift toward using "less costly munitions" and as Iran reduces the pace of its drone and missile launches.

Even so, the center concludes that "unbudgeted costs will be substantial" and will depend "on the intensity of operations and the effectiveness of Iran's retaliatory strikes."

Of the $3.7 billion spent in the opening days of the war, approximately $1.7 billion went toward air interceptors such as the Patriot missile system, while another $1.5 billion was directed at missiles and other defensive munitions. Air operations cost $125 million, maritime operations $64 million, and ground operations $7 million.

CSIS estimates, based on previous air campaigns, that it will cost more than $3 billion to replenish the munitions inventory being depleted in the war.

The estimate comes shortly after prominent fiscal expert Kent Smetters warned Fortune magazine that, beyond direct military expenditures, the U.S. economy could sustain losses of up to $210 billion as a result of the war against Iran.