The US military has spent an estimated $43.6 billion on its war with Iran through September 3, according to a new Pentagon assessment provided to Congress, with bombs, missiles and other munitions accounting for more than 60 percent of the total.
The figure offers the clearest unclassified picture yet of the financial burden of the conflict, which began on February 28. It also shows how quickly the cost has risen. The Congressional Budget Office estimated earlier this month that the war had cost the Department of Defense about $38 billion through August 1.
The latest Pentagon estimate is not a final bill. Congressional officials have warned that it leaves out several major expenses, including the cost of repairing or replacing US military facilities damaged by Iranian attacks across the region. A separate $1.5 billion request for fuel and other expenses was also not included in the $43.6 billion figure.
That means the actual financial burden on the US government is already higher than the headline figure suggests.
Munitions Account for the Largest Share
The largest expense has been the use of weapons.
The Pentagon estimates that it has spent $28.1 billion replacing munitions used during the conflict. That includes bombs, missiles and air defence interceptors fired during months of sustained combat. The figure represents more than 60 percent of the total estimated cost.
The spending has affected US weapons inventories beyond the immediate theatre of operations. Critical systems, including Patriot air defence interceptors, have been drawn from existing stocks held by American military commands in Europe and Asia.
Replacing those weapons will not simply be a matter of placing a large order and waiting for deliveries.
The Congressional Budget Office has warned that rebuilding depleted US munitions inventories could take at least five years. Its assessment points to the scale of the replenishment problem created by the conflict and the time required for manufacturers to produce sophisticated weapons at the necessary rate.
Air Force Carries the Largest Service Cost
The Pentagon’s latest disclosure also provides a service by service breakdown, offering a rare view of how the conflict has affected different parts of the US military.
The Air Force accounted for about $6.6 billion in costs through September 3. The service has operated dozens of fighter and bomber squadrons as part of the campaign, generating large expenses through aircraft operations, personnel support, maintenance and associated logistics.
The Navy’s costs reached about $2.2 billion. More than two dozen warships have been deployed in support of the conflict, creating additional expenses linked to operations at sea, fuel, maintenance and logistics.
The Army accounted for approximately $1.6 billion while sustaining forces stationed in the region.
More than 50,000 US troops have been assigned to the broader mission, adding another layer of operational and support costs as the conflict continues.
The figures do not mean that every dollar spent by the military during the period was caused directly by the war. The CBO has noted that its own estimate excludes basic military operating costs that were already included in the federal budget. Its calculation instead focuses on additional costs associated with the conflict, including weapons, equipment losses, increased flying hours and fuel.
Billions More Needed for Damaged Equipment
Weapons fired during combat are not the only source of rising expenses.
The Pentagon estimates that $4.3 billion has been required to replace combat aircraft and other military equipment that was damaged or destroyed during the conflict. That figure could change as further assessments are completed.
The cost of damaged military bases is a separate issue.
Iranian attacks have struck US facilities across the Middle East, creating repair and reconstruction bills that are not included in the $43.6 billion estimate. Congressional officials have therefore described the Pentagon figure as an undercount of the conflict’s full cost.
Those expenses could become substantial if damaged facilities require major reconstruction rather than routine repairs.
The distinction matters because the headline figure covers the Pentagon’s estimated war expenses up to September 3, not the full long term financial consequences of the conflict.
CBO Warns Costs Will Keep Rising
The Pentagon estimate arrived shortly after a separate analysis by the nonpartisan Congressional Budget Office.
The CBO calculated that the conflict had cost the Department of Defense approximately $38 billion by August 1. It estimated that continuing operations could add between $2 billion and $3 billion each month, depending on the intensity of fighting.
Under the CBO’s lower intensity scenario, monthly costs would be around $2 billion. If fighting returned to the level seen during more intense periods, the monthly figure could rise to about $3 billion or potentially higher.
The CBO also stressed that its estimates contain uncertainty because the Department of Defense did not respond to requests for information used in preparing the analysis. The budget office instead relied on government databases and publicly available reports.
The two estimates therefore measure the conflict at different points in time and use different methodologies. The CBO figure covers costs through August 1, while the Pentagon estimate extends through September 3.
Together, however, they show the rapid rise in spending as the war has continued.
Stockpiles Face a Longer Term Problem
The financial cost is only one measure of the conflict’s impact.
The depletion of American weapons inventories could affect military planning well after the fighting ends. The CBO said rebuilding depleted munitions stockpiles could take at least five years.
That concern is particularly relevant for sophisticated air defence systems. Patriot interceptors and other missile defence weapons require specialised production facilities and components, meaning output cannot necessarily be increased overnight.
The war has therefore created a problem that extends beyond the immediate cost of replacing weapons already fired.
The United States must also maintain sufficient inventories for other military commitments while rebuilding stocks used in the Iran conflict.
That creates competing demands on the Pentagon at a time when the department is already seeking additional funding.
The Bill Is Still Growing
The $43.6 billion estimate covers only spending recorded through September 3. Every additional month of combat could add billions more.
The CBO’s estimate of $2 billion to $3 billion in monthly costs provides a rough measure of what continued operations could mean for the federal budget. The figure could rise if the intensity of fighting increases.
There are also expenses that will come later.
Repairing damaged bases, replacing additional equipment, rebuilding weapons inventories and dealing with other costs that emerge after combat operations could push the final price substantially above the current Pentagon estimate.
For Congress, the figures provide a clearer view of the immediate military bill. They also raise a longer term question about how much the United States will ultimately spend to restore the equipment and stockpiles consumed during the conflict.
The Pentagon has now put the known cost at $43.6 billion through September 3, but that number does not represent the end of the bill. With weapons inventories depleted, damaged facilities still requiring assessment and combat costs continuing to accumulate, lawmakers will have to account not only for what the war has already consumed, but also for what it will take to rebuild.
How much higher will the final cost rise before the United States finishes paying for the conflict?