Missile Shortages Force U.S. to Rely on Older Weapons Against Iran

The United States appears to be relying increasingly on older ground-launched ballistic missiles for attacks on Iran, offering a new indication of the pressure the prolonged war is placing on American stocks of advanced precision weapons.

Footage released by U.S. Central Command on July 17 showed M142 High Mobility Artillery Rocket Systems, widely known as HIMARS, launching missiles against what the command described as strategic Iranian military targets. CENTCOM did not identify the weapons, reveal how many were fired or disclose the launch location.

Military analysts examining the footage identified the missiles as Army Tactical Missile Systems, or ATACMS, a weapon first developed during the Cold War and used operationally since the 1991 Gulf War. The U.S. Army has been replacing it with the newer Precision Strike Missile, known as PrSM, which offers greater range and allows launchers to carry twice as many missiles.

The Pentagon has not publicly confirmed that ATACMS were used in the latest strikes or that the decision was caused by shortages of PrSM. The available evidence nevertheless suggests that the United States may be drawing more heavily on its older reserves after consuming much of its limited stock of newly produced missiles.

Both weapons can be fired from the same HIMARS launcher, meaning U.S. forces can switch between them without deploying new equipment. Their combat capabilities, however, are substantially different.

A HIMARS launcher carries one ATACMS missile in each launch pod. The missile can strike targets at a maximum distance of around 300 kilometres. A single pod can hold two PrSM missiles, each capable of reaching more than 400 kilometres.

The newer missile therefore gives each launcher twice the immediate firepower while allowing crews to remain farther from the battlefield. That distance is particularly important in the Gulf, where American launchers may face Iranian drones, surveillance systems and retaliatory missile attacks.

The use of ATACMS would impose greater operational restrictions on the locations from which U.S. forces can strike Iran. Launchers deployed in Kuwait or other positions on the western side of the Gulf could reach targets in southwestern and coastal Iran, including military sites near Khorramshahr, Abadan and Bushehr.

Reaching targets deeper inside Iranian territory would require launchers to move closer to Iran, increasing their exposure, or would force the United States to depend on aircraft, ships and submarines carrying longer-range weapons.

The shift highlights a broader problem facing the U.S. military, in which advanced missiles can be expended much faster during an intensive war than American factories can replace them.

The Army received its first early operational PrSM missiles in late 2023, leaving only a limited period to build an inventory before the conflict with Iran began. Unlike ATACMS, which was produced in large numbers over several decades, PrSM remains in the early stages of procurement and manufacturing.

An assessment published in April by the Center for Strategic and International Studies cited an Army official as saying the entire available PrSM inventory had already been expended. Other officials disputed that account and said some missiles remained, leaving the exact stock level unclear.

The same assessment estimated that the U.S. military could still possess as many as 800 ATACMS missiles. Although the figure has not been officially confirmed, it would explain why commanders can continue conducting ground-launched ballistic missile attacks after PrSM stocks have been heavily reduced.

Army procurement documents also show the gap between the number of missiles the military ultimately wants and the relatively small number currently being produced.

The Army’s initial fiscal 2026 budget request included 45 PrSM missiles, comprising 35 Increment 1 weapons and ten Increment 2 variants. Another 107 Increment 1 missiles were financed through separate funding, raising planned procurement for the year to 152 missiles.

Those numbers remain far below the Army’s long-term objective of acquiring 3,986 Increment 1 missiles and 1,589 Increment 2 missiles. Reaching that target will require years of sustained manufacturing, even before accounting for weapons consumed in combat.

The apparent use of ATACMS does not mean the older missile is ineffective. The Army has continued testing missiles held in storage to ensure that their motors, guidance systems and launcher connections remain reliable. Some weapons in the inventory may be more than 30 years old, yet they remain capable of striking fixed military targets with considerable accuracy.

Their renewed use instead illustrates the compromises imposed by a high-intensity missile war. ATACMS provides the United States with a substantial reserve weapon that can be fired from existing launchers, allowing operations to continue as newer missile stocks decline.

It also gives commanders less range, fewer missiles per launcher and narrower choices over where launch units can safely operate.

The Iran war is therefore exposing not only the strength of the American precision-strike arsenal, but also its production limits. The United States possesses large numbers of older weapons, though the growing dependence on those reserves suggests that its newest missile systems are being consumed faster than they can be replenished.