What is CSIS?: The Center for Strategic and International Studies is a Washington, D.C. bipartisan think tank founded in 1962. It employs around 220 researchers covering defence, geopolitics, technology, and economics, and is consistently ranked among the world's most influential foreign-policy institutions.Source: CSIS
How much has Operation Epic Fury cost according to CSIS?: CSIS estimated the first 100 hours of Operation Epic Fury at $3.7 billion, roughly $891 million per day. By the end of three weeks, CSIS put the running total at approximately $19 billion. The Pentagon later requested a $200 billion congressional supplemental to fund continued operations.Source: CSIS / Pentagon
Is CSIS bipartisan or left-wing?: CSIS describes itself as bipartisan and draws funding from US government agencies, defence contractors, and allied governments. Both progressive and conservative critics have used its war-cost figures to argue against the $200 billion supplemental, suggesting its data is treated as credible across the political spectrum.Source: CSIS
What did CSIS say about the $200 billion war bill?: CSIS did not take a position on the bill directly, but its $900 million-per-day burn-rate estimate was central to both sides of the congressional debate. Fortune calculated that $200 billion funds roughly 140 more days of operations at the CSIS-derived rate.Source: Fortune / CSIS
How does CSIS differ from the Heritage Foundation on Iran war costs?: CSIS provides independent financial accounting of the war, publishing burn-rate estimates used in Senate hearings. The Heritage Foundation has opposed the $200 billion supplemental on political grounds, arguing the intra-party revolt reflects genuine fiscal conservatism rather than strategic disagreement.Source: CSIS / Heritage Foundation

Background

The Center for Strategic and International Studies (CSIS) is a bipartisan think tank founded in 1962 in Washington, D.C., originally affiliated with Georgetown University and fully independent since 1987. It employs roughly 220 researchers across defence, geopolitics, technology, and economics, and is consistently ranked among the world's most influential foreign-policy institutions. Its funding spans US government contracts, defence contractors, and allied governments; a mix critics note creates potential conflicts of interest on the topics it analyses.

In the Iran conflict, CSIS became the primary public authority on war expenditure. Its estimate that the first 100 hours of Operation Epic Fury cost $3.7 billion (~$891 million per day) was the first credible independent accounting of the campaign . At three weeks in, CSIS put the running total at $19 billion , figures cited in Senate appropriations hearings, NPR, and Fortune during debate over the Pentagon's $200 billion supplemental request .

CSIS's centrality to the cost debate puts it at an awkward intersection: its numbers are politically volatile, yet its defence-contractor funders have a direct interest in continued operations. The Heritage Foundation has contested the supplemental bill on different grounds, illustrating that war-funding scepticism now spans the political spectrum .

Source Material

Center for Strategic and International Studies CSIS Official Website Think tank CSIS says US has spent $3.7 billion on Iran campaign in first 100 hours

How the World Sees Them

Iran

Tehran monitors CSIS analyses closely for signals of weakening US resolve, treating high published costs as evidence the campaign is domestically unsustainable. Its state media has amplified the $900 million-per-day figure as a narrative of imperial overstretch.

European Union

EU governments track CSIS cost assessments to gauge how long US domestic political will can hold. A funding breakdown in Washington would force rapid European reassessment of its own strategic posture toward the Iran conflict.

United States (pro-war bloc)

CSIS data anchors congressional testimony in favour of the $200 billion supplemental, lending institutional credibility to continued operations. Its burn-rate figures are the only independent cross-check on Pentagon cost claims, cited in Senate hearings and major media.

United States (anti-war bloc)

Libertarian and progressive critics use the same CSIS numbers to argue Operation Epic Fury is unaffordable for the American taxpayer. MAGA sceptics and progressive senators cite the $19 billion figure in equal measure when opposing the supplemental bill.