The United States has already spent an estimated $3.7 billion in the first 100 hours of its war against Iran, highlighting the enormous financial burden of the rapidly escalating conflict. The figure, averaging nearly $900 million per day, largely reflects the heavy use of advanced munitions and high-end weapons systems.
The assessment comes from the Washington-based think tank the Center for Strategic and International Studies (CSIS), whose researchers analysed the early stages of the campaign as the war entered its seventh day.
Massive Costs Driven by Advanced Weapons
According to the CSIS analysis, the soaring costs are primarily tied to the extensive use of sophisticated military hardware during the opening phase of the air campaign.
Researchers Mark Cancian and Chris Park estimated that the United States spent roughly $891 million per day during the first 100 hours of operations.
However, only a small portion of these expenses had been planned for in advance. Of the total estimated cost, about $3.5 billion was not included in the Pentagon’s existing budget, meaning the US Department of Defense will likely have to request additional funding to sustain the war effort.
Such a request could quickly turn into a political challenge for the administration of Donald Trump, especially as the conflict intensifies.
Pentagon May Face Political Pressure
The analysts warned that the need for new funding could become a focal point for political opposition in Washington.
Rising inflation, domestic cost-of-living pressures and increasing fuel prices linked to the conflict are already weighing on public sentiment. These factors could weaken support among American voters as the war continues.
The issue is also creating divisions within Trump’s political base, particularly among supporters who backed his long-standing promise to avoid “foreign wars”.
Thousands of Munitions Already Used
While the United States Department of Defense has released only limited operational details, the CSIS study estimates that more than 2,000 munitions were used during the first 100 hours of the campaign.
Replacing those weapons could cost an additional $3.1 billion, pushing daily replenishment expenses to roughly $758 million.
The researchers based their calculations on estimates from the US Congressional Budget Office, adjusting the figures for inflation, force size and the increased pace of operations.
Costs Expected to Rise Further
The financial burden may grow even larger in the coming days. Pete Hegseth has signalled that the US military campaign could intensify, with more fighter squadrons, expanded defensive systems and increasingly frequent bomber operations.
Although air campaigns often slow after the initial high-intensity phase, the researchers warned that “unbudgeted costs will be substantial” as long as the conflict continues.
