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US Iran war cost hits $29bn on 12 May

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Bloomberg and CBS News reported on 12 May that the US war against Iran has cost $29 billion, up $4 billion from the $25 billion figure the Pentagon briefed to Congress two weeks earlier. None of the spending has a signed presidential instrument behind it.

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Key takeaway

Bloomberg and CBS put the US Iran war cost at $29bn on 12 May, $4bn above the Pentagon's figure.

Bloomberg and CBS News reported on 12 May 2026 that the US war cost against Iran has reached $29 billion, up $4 billion from the $25 billion figure the Pentagon briefed to Congress approximately a fortnight earlier ¹. The figure landed on the same day Pete Hegseth told Senate Appropriations that Article 2 covers Iran strikes and no AUMF is required, a juxtaposition that puts $4 billion every two weeks alongside zero signed presidential instruments.

$4 billion fortnightly is the build cost of a Virginia-class submarine every two weeks, sustained for 75 days without a vote, a finding, or a signed executive order. The operational layer behind the burn rate is CENTCOM's blockade, which had logged 61 cumulative vessel redirections and four disabled vessels by 10 May . The constitutional layer is now Article 2 alone. Trump's contradictory 8 May Truth Social posts and his 11 May Oval Office military-options list are the rhetorical surface of the same unsigned arithmetic.

Senate Appropriations becomes the only operating venue for legislative pressure on Iran policy because, under the administration's stated reading, appropriators can defund but cannot deauthorise. Murkowski's unfiled AUMF sits between a $4 billion fortnightly burn rate the appropriators can in principle constrain and a doctrine telling them they cannot deauthorise it.

Deep Analysis

In plain English

The United States has spent $29 billion fighting in Iran since the war began on 28 February. Bloomberg and CBS News reported that figure on 12 May. To put it in perspective: the cost of building a nuclear submarine is roughly $4 billion, and the US is spending that amount every two weeks on this conflict. When governments go to war, they normally pass special legislation, called an Authorisation for Use of Military Force, that both approves the war and sets a budget. In this case, Congress has passed no such authorisation. The money is being spent under normal Pentagon budget authority, which the Senate Appropriations Committee oversees. That committee, the one that writes the military's annual budget, is now the main place in Congress where any attempt to question or limit the war can actually happen. The committee cannot formally vote to end the war without the authorisation it was denied, but it can refuse to approve new war spending.

Source Landscape

This story draws on mixed-leaning sources from United States

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Primary parallel: The early Korean War offers the structurally closest precedent: Truman committed forces in June 1950 under UN Security Council authority without seeking congressional authorisation, and the war cost approximately $30 billion in 2026 dollars before Congress passed its first relevant appropriation.

The 2003 Iraq War cost $53 billion in its first year, but that spending was authorised by a formal AUMF passed by Congress on 16 October 2002; the Iran campaign's running total across 75 days is on a comparable monthly trajectory with no such instrument behind it.

Counter-parallel: The 1991 Gulf War cost $61 billion total, with allied burden-sharing covering $48 billion of that. The Iran campaign has no comparable allied cost-sharing mechanism; the European coalition is building a separate post-war framework but has not contributed to CENTCOM's operational costs, leaving the entire war bill on the US Treasury alone.

The $4 billion fortnightly burn rate maps onto specific CENTCOM cost drivers that defence economists have publicly modelled. A Carrier Strike Group in operational tempo costs approximately $25 million per day.

Two CSGs in the Gulf run at roughly $3.6 billion over 75 days before adding TLAM (Tomahawk Land Attack Missile) stocks, JASSM (Joint Air-to-Surface Standoff Missile) procurement to replace expended rounds, aerial refuelling, and SOF (Special Operations Forces) logistical support. The total war-cost figure implies the kinetic campaign has consumed approximately $10-12 billion in munitions and replenishment procurement on top of operating costs.

The constitutional asymmetry sharpens the fiscal significance. Senate Appropriations can cut the OCO (Overseas Contingency Operations) transfer or refuse a supplemental appropriations request; these are the practical tools for constraining a war the executive branch claims it needs no authorisation for.

The $4 billion fortnightly rate gives appropriators a concrete figure to defund in the next continuing resolution or supplemental. Senator Collins, who chairs Senate Appropriations and sat on the panel where Hegseth testified, has the authority to attach conditions to the next Pentagon spending instrument even if she cannot file an AUMF.

Sources:Foreign Policy Journal·Foreign Policy Journal

Mentions:CBS News →Donald Trump →CENTCOM (US Central Command) →Truth Social →United States →AUMF →Virginia →Iraq →Iran →US Treasury →Pete Hegseth →Senate Appropriations Committee →Gulf War →EU Article 102 →Pentagon →Bloomberg →

First Reported In

Update #96 · Hegseth: no AUMF needed. Trump flies east

Foreign Policy Journal· 13 May 2026

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Causes and effects

Caused by

CENTCOM redirections rise to 61, disabled count holds at four

CENTCOM's 61 cumulative redirections (ID:3211) are the operational context for the $29bn war cost now reported by Bloomberg and CBS

Occurred 10 May 2026

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This Event

US Iran war cost hits $29bn on 12 May

A $4 billion fortnightly burn rate with no signed authorisation behind it gives appropriators the leverage that authorisers no longer have under Hegseth's Article 2 reading.

Different Perspectives

Markets

Brent crude rose 2.2 per cent to $96.34 on 10 June, reversing a 7 per cent weekly decline built on deal optimism, as the overnight exchange repriced the Strait of Hormuz risk premium in a single session. The move reflects transit-risk repricing rather than supply shock: Iran's exports had already collapsed to below 300,000 barrels per day.

Pakistan

Pakistan's Naqvi channel, the only mediation track carrying both civilian and military buy-in, was stress-tested by live ordnance within 48 hours of the 6-7 June Tehran visit. Whether Washington informed Islamabad of the imminent strike plan while Naqvi was in Tehran remains undisclosed, putting the channel's neutrality under scrutiny.

Kuwait

Kuwait hosted the third Iranian strike on its soil since the 3 June airport drone attack, with Ali Al Salem airbase targeted in the three-country salvo. Its recent $1.98 billion Anduril Anvil counter-drone purchase signals it is rearming rather than reconsidering its hosting posture.

Bahrain

Bahrain absorbed the IRGC barrage via PAC-3 intercepts with its magazine already at 87 per cent depletion and no resupply before 2027. Sounding air-raid sirens over Manama, it faced the intercept burden with the thinnest defensive stack in the Gulf coalition.

Jordan

Jordan reported all five incoming missiles intercepted with no injuries and no damage, a clean defensive performance that strengthens Amman's case for staying in the Western coalition without escalating its own posture. It now sits on Iran's target list for the first time despite not being a party to the Abraham Accords confrontation.

Iran / IRGC

Foreign Minister Araghchi posted on X that US forces should 'leave our region if you want to be safe' and framed the exchange as a US defeat, while the IRGC claimed 21 targets hit and an F-35 hangar destroyed. The claims serve a domestic and Arab-audience framing rather than a verified battle-damage assessment.