Iran War Costs Hit $37.5 Billion as U.S. Weapons Shortfalls Strain Defence Supply Chains

A new U.S. government watchdog report has highlighted the growing financial and logistical cost of the Iran conflict, revealing strategic weapons shortages, supply-chain bottlenecks and extensive damage to American military and diplomatic infrastructure across West Asia.

The Pentagon Inspector General’s first report on Operation Epic Fury, released on September 14, provides the fullest official accounting so far of the conflict’s impact on US forces. The report covers operations through June 30 and warns that heavy weapons expenditure has created “strategic inventory shortfalls” while exposing bottlenecks in the US defence industrial base.

The findings add a new economic dimension to the continuing conflict, as Washington faces substantial replacement, repair and resupply requirements while the fighting continues to affect energy markets and regional trade routes.

U.S. Weapons Stockpiles Face Growing Pressure

According to the watchdog report, the conflict has placed significant pressure on advanced US weapons inventories. The report said munitions expenditure revealed industrial-base bottlenecks affecting the ability to replenish supplies. Experts cited by AP have previously estimated that rebuilding some advanced missile and interceptor stocks to prewar levels could take around three years.

The scale of equipment losses has also been significant. Up to 30 MQ-9 Reaper drones, each costing around $30 million, were destroyed. Seven KC-135 refuelling aircraft were also damaged or destroyed, including five hit by Iranian munitions while on the ground in Saudi Arabia.

The report’s findings conflict with repeated public statements from Pentagon officials that US forces have sufficient weapons for current operations. President Donald Trump also said on Monday that the United States is producing and delivering weapons at a high rate.

Damage Spreads Across U.S. Military Infrastructure

Iranian attacks also damaged or destroyed hundreds of buildings and other structures at US installations across Kuwait, Bahrain, Qatar, the UAE, Saudi Arabia, Iraq, Oman and Jordan.

The damage to Bahrain is particularly important because the US naval facility there serves as a major regional logistics hub. Following attacks, US Central Command shifted some supply operations to alternative locations, including Diego Garcia in the Indian Ocean. The watchdog said this created logistics cycles lasting 14 to 18 days, potentially increasing the cost and complexity of maintaining military operations in the region.

Such disruptions go beyond immediate repair costs. Longer supply routes can require additional transport capacity, fuel, personnel and inventory, increasing the financial burden of an extended conflict.

Diplomatic Facilities Also Suffered Major Damage

The financial impact was not limited to military assets.

US diplomatic facilities in Iraq, Kuwait, Saudi Arabia and the United Arab Emirates suffered an estimated $184 million in physical damage, according to the report. The State Department separately reported $113 million in other conflict-related costs, including contingency measures and evacuations. Around 9,000 US citizens were evacuated from countries in the Middle East and Europe after the conflict began.

Iran Conflict Pushes Costs Higher

Defense Secretary Pete Hegseth told Congress in late July that the war had already cost approximately $37.5 billion. That figure illustrates the scale of spending associated with military operations, weapons use, equipment losses and supporting infrastructure.

At the same time, the US recorded more than $44 billion in emergency and non-emergency military sales during the period covered by the report, with Saudi Arabia accounting for the largest share. Other regional states, including Qatar, Kuwait, the UAE and Israel, also received significant military equipment and support.

This creates an unusual combination of rising wartime expenditure and stronger defence demand, but it also highlights the pressure placed on the US industrial base to manufacture replacement weapons quickly.

Why the Report Matters for Markets

The report has implications beyond US defence policy. Prolonged military spending can increase pressure on government finances, while weapons shortages and supply-chain constraints can affect procurement schedules and defence-sector costs.

The conflict is also unfolding alongside severe disruptions to Middle Eastern energy infrastructure and shipping routes. Higher oil prices can raise inflation expectations, potentially influencing central-bank decisions and financial-market volatility.

For investors, the key issue is whether the conflict remains contained or leads to sustained increases in military spending, energy prices and supply-chain disruptions. A prolonged conflict could keep pressure on government budgets while reinforcing demand for defence equipment and strategic commodities.

What Markets Will Watch Next

Investors will continue monitoring US defence spending, oil prices, Treasury yields, the US dollar and regional geopolitical developments. Any further deterioration in US weapons inventories or expansion of the conflict could increase expectations for additional government spending.

For now, the Inspector General’s report provides the clearest official evidence yet that the Iran conflict has imposed substantial financial and logistical costs on the United States, while exposing vulnerabilities in the supply chain supporting advanced weapons.