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

The war between the United States (US) and Iran has finally begun to yield positive news. Washington and Tehran are reported to have 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 deal is said to be formally signed in Switzerland on Friday. Trump even stated that all points of the agreement with Iran have been completed and are ready to be finalised. Meanwhile, Sharif said the pact includes a permanent cessation of military operations on all conflict fronts, including in Lebanon. Although the final details have not been published, the agreement is said to reopen the Strait of Hormuz, the vital global energy trade route that has been affected by the war for months. Additionally, the US naval blockade of Iranian ports will also be ended. However, behind the peace news, the war over the past few months has left a heavy burden on the US military. One of these is the significantly depleted stock of ammunition and missiles. Citing an analysis by the Center for Strategic and International Studies (CSIS), the bombing of Iran by the US military and the launch of US air defence system missiles to repel Iranian counterattacks during three months of war have drained Washington’s supply of several key munitions. CSIS noted that the US fundamentally still has enough ammunition to face various scenarios in a war against Iran. However, the massive use in the conflict has created new vulnerabilities, especially if the US has to face another conflict in the Western Pacific region. In other words, the main problem for the US is not simply whether it still has missiles or not. The bigger issue is how quickly Washington can replenish the weapons stockpiles that have been used during the war. US Secretary of Defence Pete Hegseth previously stated that the process of replenishing weapons inventories would take months to years, depending on the type of weapon system. CSIS analysis shows a similar picture. One of the most heavily used munitions in the war against Iran was the Tomahawk Land Attack Missile (TLAM). CSIS estimates that the US used more than 1,000 Tomahawk missiles during the conflict. This number is very large compared to the current annual production capacity, which is estimated at around 600 missiles per year, although the target under the US defence industrial framework could reach 1,000 missiles per year. The problem is that production cannot surge instantly. CSIS noted that with current delivery projections, US Tomahawk stockpiles are only expected to return to pre-war levels by late 2030 to early 2031. This means that for this single missile type alone, the US needs about four to five years to fully restore its stockpile to pre-Iran war levels. Beyond Tomahawk, air defence systems such as Patriot and THAAD are also in the spotlight. These two systems are critical because they are used to intercept missile attacks and protect US and allied assets. For Patriot, CSIS estimates the US used around 1,060 to 1,430 missiles during the war. In contrast, deliveries to the US inventory in fiscal year 2026 are only around 172 units. The US government then requested the procurement of 3,203 Patriot missiles in the fiscal year 2027 budget. However, large deliveries from this procurement are only expected to begin arriving in 2029. CSIS estimates that US Patriot stockpiles will only return to pre-war levels around mid-2029. Meanwhile, for THAAD, the US is estimated to have used around 190 to 290 interceptors. This figure is also quite large, considering the current annual production capacity is estimated at only around 96 units, although the future capacity target could reach 400 units per year. US THAAD stockpiles are estimated to recover only by mid to late 2029. For naval defence missiles, CSIS highlighted the use of SM-3 and SM-6. Neither was used as extensively as Tomahawk, Patriot, or THAAD, but they remained an important part of the war due to their role in 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 of 214 units in fiscal year 2027, the stockpile of this missile is expected to return to pre-war levels by early 2029. Meanwhile, SM-6 usage is estimated to have reached 190 to 370 units. The US requested the procurement of 540 units in the 2027 budget, with current annual production capacity around 239 units and a future target of 500 units. CSIS estimates SM-6 stockpiles will only recover by late 2028 to early 2029. Not all munitions require years to replace. CSIS noted two types of weapons, 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, its stockpile is expected to return to pre-war levels by mid-2027. This is because deliveries from previous procurement are quite substantial. As for the PrSM or Precision Strike Missile, it is estimated that around 40 to 70 units were used. Its stockpile is projected to recover faster, by late 2026. However, CSIS noted that the initial PrSM stockpile was indeed still low because this weapon system has only recently begun production.