Iran and US Make Peace: How Many Missiles and Munitions Has America 'Burned' Through?

The war between the United States and Iran has finally begun to yield positive news. Washington and Tehran have reportedly reached an agreement to end the conflict that has lasted for several months.

The news was announced directly by US President Donald Trump and Pakistani Prime Minister Shehbaz Sharif, who acted as a mediator in the negotiation process. The peace agreement is said to be officially signed in Switzerland this coming Friday.

Trump stated that all points of the agreement with Iran have been completed and are ready for finalisation. Meanwhile, Sharif mentioned that the pact includes a permanent cessation of military operations across all conflict fronts, including Lebanon.

Although the final details have not yet been published, this agreement is expected to reopen the Strait of Hormly, a vital global energy trade route that has been impacted by war for months. Additionally, the US naval blockade of Iranian ports will be lifted.

However, behind the news of peace, the recent months of warfare have left a heavy burden on the US military. One of the primary issues is the significant depletion of ammunition and missile stocks.

According to an analysis by the Centre for Strategic and International Studies (CSIS), US bombing raids against Iran and the deployment of US air defence missile systems to intercept Iranian counter-attacks during the three-month war have drained Washington’s supplies of several critical munitions.

CSIS noted that while the US essentially still possesses enough ammunition to face various scenarios in a war against Iran, the massive usage during this conflict has created new vulnerabilities, particularly if the US must face another conflict in the Western Pacific region.

In other words, the primary issue for the US is not merely whether they still possess missiles, but how quickly Washington can replenish the weapon stocks used during the war. US Secretary of Defence Pete Hegseth previously stated that the process of replenishing weapon inventories could take months to years, depending on the type of weapon system. CSIS analysis presents a similar picture.

One of the munitions most heavily used by the US in the war against Iran is the Tomahawk Land Attack Missile (TLAM). CSIS estimates that the US used more than 1,000 Tomahawk missiles during the conflict.

This figure is massive compared to annual production capabilities. Current Tomahawk production capacity is estimated at around 600 missiles per year, although the target capacity within the US defence industry framework could reach 1,000 missiles per year. The problem is that production cannot surge immediately. CSIS noted that, based on current delivery projections, US Tomahawk stocks are only expected to return to pre-war levels by late 2030 or early 2031. This means that for this single type of missile, the US requires approximately four to five years to fully restore its stocks to pre-Iran war levels.

In addition to the Tomahawk, air defence systems such as Patriot and THAAD are also under scrutiny. These two systems are critical as they are used to intercept missile attacks and protect US and allied military assets.

For the Patriot system, CSIS estimates the US used approximately 1,060 to 1,430 missiles during the war. Meanwhile, deliveries to the US inventory for the 2026 fiscal year are only around 172 units. The US government has subsequently requested the procurement of 3,203 Patriot missiles in the 2027 fiscal year budget. However, large-scale deliveries from this procurement are not expected to arrive until 2029. CSIS estimates US Patriot stocks will only return to pre-war levels around mid-2029.

As for THAAD, the US is estimated to have used around 190 to 290 interceptors. This figure is also significant, given that current annual production capacity is estimated at only about 96 units, even though future target capacity could reach 400 units per year. US THAAD stocks are expected to recover only between mid to late 2029.

Regarding naval defence missiles, CSIS highlighted the use of SM-3 and SM-6. Both were not used as extensively as the Tomahawk, Patriot, or THAAD, but remained vital to the war regarding warship defence and missile interception. The US is estimated to have used around 130 to 250 SM-3 missiles during the Iran war. With a procurement request for 214 units in the 2027 fiscal year, stocks of these missiles are expected to return to pre-war levels by early 2029.

Meanwhile, the use of SM-6 is estimated to have reached 190 to 370 units. The US has requested the procurement of 540 units in the 2027 budget, with current annual production capacity at around 239 units and a future target of 500 units. CSIS estimates SM-6 stocks will only recover between late 2028 and early 2029.

Not all munitions require years to replace. CSIS noted that two types of weapons, namely JASSM and PrSM, have relatively faster recovery times.

For JASSM, the US is estimated to have used more than 1,100 missiles during the war. Despite the large number, stocks are expected to return to pre-war levels by mid-2027, as deliveries from previous procurements are substantial. As for the PrSM (Precision Strike Missile), an estimated 40 to 70 units were used. Stocks are projected to recover faster, by the end of 2026. However, CSIS noted that initial PrSM stocks were low because this weapon system has only just entered production.