The six-month-old U.S. war with Iran has cost the Pentagon an estimated $38 billion through August 1, 2026, according to a new analysis from the nonpartisan Congressional Budget Office (CBO). The agency estimates that the cost could increase by around $2 billion to $3 billion every month if military operations continue.

The financial cost is only one part of the growing pressure on the United States. The conflict has also reduced U.S. weapons stockpiles, increased energy prices and created concerns about military readiness for potential future conflicts.

U.S. War Spending Reaches $38 Billion

The CBO’s September 15 report examined the costs associated with U.S. combat operations against Iran. Its estimate covers expenses through August 1.

A large portion of the spending comes from the rapid use of military equipment and ammunition during the conflict. The CBO estimates that combat-related costs include billions of dollars for munitions, equipment losses, additional flying hours and jet fuel.

The $38 billion figure is close to the $37.5 billion estimate previously given by Defense Secretary Pete Hegseth during a Senate hearing in July.

War Could Cost Billions More Each Month

The financial burden could continue growing if the conflict remains active.

The CBO estimates that continued operations could cost approximately $2 billion per month during lower-intensity fighting. If the conflict remains at the level seen during July, monthly costs could approach $3 billion.

That means another six months of fighting could potentially add many billions of dollars to the U.S. government’s military expenses.

The final cost could also be higher because the CBO estimate does not include every expense associated with the conflict.

U.S. Weapons Stockpiles Under Pressure

One of the most important concerns highlighted by the report is the effect of the war on U.S. military ammunition supplies.

The conflict has consumed large quantities of precision-guided weapons and missile interceptors. The CBO said replenishing some depleted stockpiles could take years.

The issue is important because the United States maintains military commitments around the world.

A shortage of critical weapons could potentially limit the Pentagon’s ability to respond quickly if another major conflict develops.

Pentagon Requests Emergency Funding

The Pentagon has already sought additional funding to rebuild depleted weapons supplies.

Defense Secretary Pete Hegseth previously requested nearly $90 billion in emergency funding for replenishing munitions and other military resources. He warned lawmakers that additional funding was needed to address potential shortfalls.

The White House and Pentagon, however, have disputed claims that the U.S. military lacks the resources needed to achieve its current objectives. Pentagon officials have said the military has sufficient weapons and ammunition for the administration’s stated strategic goals.

Energy Prices Add to Economic Pressure

The war is also affecting the global economy through energy markets.

The Strait of Hormuz has been heavily disrupted during the conflict. Before the war, roughly 20% of global oil supplies traveled through the waterway, making it one of the world’s most important energy routes.

Disruptions around the strait have contributed to higher energy prices.

Higher oil prices can increase transportation and production costs, which can eventually affect consumers through more expensive fuel and other goods.

Inflation Could Rise in 2027

The economic impact could continue even if military spending eventually slows.

According to the CBO, the war could increase U.S. inflation by approximately 0.5 percentage points during the first three months of 2027.

That creates another challenge for policymakers because higher energy costs can contribute to broader price increases across the economy.

Concerns About Future Military Readiness

The cost of the Iran war has also raised questions about U.S. military readiness.

The CBO said depleted stocks of critical munitions could affect the Pentagon’s ability to respond to another major conflict, including a potential confrontation involving China and Taiwan.

This does not mean that the United States is unable to respond to another crisis. Instead, the report highlights the time and financial resources that may be required to rebuild supplies after months of intensive combat.

Human and Infrastructure Costs

The financial figures do not capture the entire impact of the conflict.

Reuters reported that 18 U.S. military service members have died in the war. The Pentagon has also suffered damage to military facilities and aircraft in the region.

The CBO’s estimate also excludes some recent attacks and the potential borrowing costs associated with financing the war. As a result, the overall economic burden could ultimately be higher than the $38 billion figure.

What Happens If the War Continues?

The future cost will depend heavily on the intensity and duration of the conflict.

If fighting decreases, monthly military expenses could fall. If operations intensify, costs could increase beyond current CBO estimates.

Several factors will therefore be important to watch:

• The duration of the conflict
• U.S. military operations
• The situation around the Strait of Hormuz
• Global oil prices
• Weapons replenishment costs
• Inflation in the United States
• Diplomatic efforts between Washington and Tehran

Conclusion

The $38 billion cost of the Iran war highlights the growing financial and military pressures facing the United States. According to the Congressional Budget Office, continued combat could add another $2 billion to $3 billion each month, while rebuilding depleted weapons stockpiles could take years.

The conflict is also affecting energy markets and could contribute to higher inflation in 2027. At the same time, questions about military readiness are becoming more important as U.S. weapons supplies are replenished.

The ultimate cost of the war will depend on how long the conflict continues and whether diplomatic efforts can reduce military operations. For now, the CBO’s estimate provides a clear indication that the financial consequences are already substantial.