U.S. Spending Soars in Iran Conflict’s First 100 Hours

In the first 100 hours of the joint U.S.–Israeli offensive against Iran, Washington has reportedly incurred a staggering expenditure of approximately $3.7 billion, averaging nearly $891 million per day. Analysts attribute this colossal cost primarily to the extensive use of munitions in the opening stages of the conflict.

A detailed study conducted by the Washington-based think tank Center for Strategic and International Studies highlights the unprecedented financial demands of the campaign. As of Friday, the conflict has entered its seventh day, with the United States continuing to strike Iranian targets using stealth bombers and advanced weaponry.

Budget vs. Unauthorised Expenditure

Researchers Mark Cancian and Chris Park reported that only a small fraction of the $3.7 billion spent was initially allocated in the federal defence budget. Roughly $3.5 billion represents off-budget spending, implying that the Pentagon will soon need to request additional funds. The reliance on unapproved expenditure could pose a political challenge for the Trump administration, particularly amidst opposition from anti-war groups.

The surge in costs, combined with domestic concerns over living expenses, inflation, and rising fuel prices, may reduce public support for the war. Even staunch proponents of the administration’s “America First” doctrine are reportedly showing signs of division.

Donald Trump had pledged to avoid foreign conflicts during his campaign, promising MAGA supporters a focus on domestic priorities rather than engagement in overseas wars.

Because the Department of Defense has released limited information, the CSIS analysis relies on Congressional Budget Office assumptions regarding operational and support costs per unit.

Munitions Usage and Ongoing Costs

During the initial 100 hours of conflict, over 2,000 munitions were reportedly deployed. Replenishing an equivalent stockpile is estimated to cost an additional $3.1 billion, adding around $758 million per day in ongoing expenditure.

Pentagon officials, including Secretary of Defense Pete Hegseth, have indicated that bombing operations on Iran are set to “dramatically intensify,” incorporating additional fighter squadrons, enhanced defensive capabilities, and frequent stealth bomber strikes. Analysts note that even as initial bombing intensity typically tapers, off-budget spending is projected to remain substantial.

Humanitarian Toll

The human cost of the conflict has already been severe. According to the Iranian Red Crescent, over 1,332 individuals have died in Iran since the offensive began, including at least 181 children, according to UNICEF.

Meanwhile, the Lebanese Ministry of Public Health reports that at least 123 civilians have been killed in Israel’s attacks on Lebanon this week, as repeated bombardments intensify. Additionally, six U.S. military personnel, eleven Israeli citizens, and nine residents of Gulf Arab countries have reportedly lost their lives since the outbreak of hostilities.

Experts warn that while this offensive is not analogous to past operations, such as the Venezuela mission targeting Nicolás Maduro, the scale of unbudgeted spending and humanitarian impact is historically unprecedented. As the conflict continues, the Pentagon may face mounting pressure to secure additional funding while managing domestic political and logistical challenges.