The cost of the first 100 hours of the U.S. military campaign against Iran is projected to be around $3.7 billion, exceeding $890 million per day, according to a report released by the Center for Strategic and International Studies (CSIS) on Thursday. The analysis highlights that less than $200 million of these costs are operational expenses that have already been included in the Pentagon's budget. The significant remaining amount, estimated at $3.54 billion, is likely to necessitate additional funding from the Department of Defense, either through a supplemental appropriations bill or another legislative measure to align the budget. Apart from operational and support costs, the report indicates that major expenses are anticipated to involve the replacement of munitions. This aspect is crucial considering concerns surrounding U.S. interceptor missile stockpiles and those of its allies. The ongoing military efforts may strain these munitions supplies, particularly as the campaign continues and the demand for replacements grows. In addition to munitions, the costs also reflect equipment losses, with notable incidents such as the downing of three F-15 aircraft due to friendly fire incidents. This situation emphasizes the financial burden not only on the military's logistical requirements but also on the overall defense posture of the United States in the context of ongoing conflicts in the region, which may have broader implications for U.S. military strategy and funding.