An analysis by the Washington think tank Center for Strategic and International Studies (CSIS) estimates the United States‑Israel campaign against Iran has cost about $3.7 billion in its first 100 hours — roughly $891.4 million per day — driven largely by heavy use of munitions. The conflict entered its seventh day as U.S. forces used stealth bombers and advanced weapons systems.
CSIS researchers Mark Cancian and Chris Park report that only a small share of that $3.7 billion had been previously budgeted; roughly $3.5 billion remains unbudgeted. That gap means the Pentagon will likely need to request additional funding, a politically sensitive step that could become a focus of opposition to the campaign. Rising domestic concerns about the cost of living, inflation, and higher fuel prices tied to the conflict are likely to erode public support and are reported to be straining former president Trump’s “America First” base, which had promised to avoid foreign wars.
Because the Department of Defense has provided limited operational detail, CSIS based its figures on Congressional Budget Office estimates for operations and support costs by unit, adjusted for inflation and unit size, and added 10 percent to account for a higher operational tempo. The analysis estimates more than 2,000 munitions of various types were expended in the first 100 hours and calculates a $3.1 billion cost to replenish those munitions on a like‑for‑like basis, with replenishment spending rising by about $758.1 million per day.
U.S. Defense Secretary Pete Hegseth is quoted as saying the bombardment is “about to surge dramatically,” with additional fighter squadrons, defensive capabilities and bomber pulses expected. CSIS notes that while air campaigns sometimes slow after an intense opening phase, the unbudgeted costs in this case are likely to remain substantial. Unlike some recent U.S. operations where most expenses had been anticipated and budgeted, this campaign is likely to require new funds. The report suggests the administration may seek a supplemental appropriation to cover military and other emergency expenses, as was done early in the Iraq and Afghanistan wars, but warns such requests will invite political contention.
The conflict has produced a severe human toll. Iranian authorities and aid agencies report more than 1,332 people killed in Iran since the strikes began, with UNICEF saying at least 181 of the dead were children. Lebanon’s health ministry reports at least 123 killed in a fresh wave of strikes. At least six U.S. service members, 11 people in Israel, and nine people in Gulf Arab countries have also died.