Can the US Fight Another Major War as Iran Drains Patriot THAAD and Tomahawk Missile Stocks?.

The U.S. military’s sustained strike and missile-defense campaign against Iran is consuming Patriot and THAAD interceptors, Tomahawk cruise missiles, and other precision weapons at a rate that could weaken readiness for another major conflict. Assessments by the Center for Strategic and International Studies (CSIS) indicate that rebuilding several critical inventories could take years, turning ammunition depth into a growing operational constraint for U.S. forces.

The immediate concern extends beyond replacing weapons fired against Iran, as Washington must retain enough long-range strike and air-defense capacity to deter or fight China in the Indo-Pacific. A prolonged missile-intensive campaign could therefore expose a central vulnerability in U.S. war planning: whether its defense industrial base can replenish high-end munitions fast enough to sustain operations across more than one theater.

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A U.S. Army Terminal High Altitude Area Defense (THAAD) launching station deployed in Israel during a joint U.S.-Israeli exercise on March 4, 2019. Designed to intercept ballistic missiles during their terminal phase of flight, THAAD has become increasingly important to U.S. missile-defense operations as sustained threats from Iran place greater pressure on American interceptor inventories and raise concerns over available stocks for other potential contingencies. (Picture source: U.S. DoD)

On July 27, 2026, CSIS estimated that continued operations associated with the Iran war had reduced the U.S. Patriot inventory to below 1,000 interceptors and the THAAD missiles stockpile to approximately 250. Although these figures are analytical estimates rather than official Pentagon stockpile disclosures, they highlight an operational problem extending far beyond the Middle East: how long the United States can sustain missile-intensive combat while maintaining sufficient reserves for another major theater.

The military significance is not whether the United States is about to exhaust every missile in its inventory. The more immediate concern is magazine depth, meaning the number of engagements U.S. forces can sustain before ammunition availability begins restricting commanders' operational choices.

That distinction immediately connects the Iran war to Indo-Pacific readiness. A conflict involving China could require the United States to defend air bases, ports, logistics hubs, headquarters and forward-deployed forces against sustained ballistic and cruise missile attacks while simultaneously conducting long-range strikes against Chinese missile forces, air defenses, command networks and supporting infrastructure.

If significant quantities of the same high-end weapons required for those missions are consumed in the Middle East, the Pentagon faces what is effectively a two-war ammunition problem. The United States can remain fully capable of prosecuting the Iran campaign while reducing the margin available for an unexpected China conflict before depleted inventories are rebuilt.

This is particularly important for missile defense. A Patriot battery may retain its radar, engagement-control equipment and launchers, but its ability to protect an air base, headquarters, logistics hub or troop concentration ultimately depends on sufficient interceptors being available for repeated engagements.

The Iran campaign is demonstrating that problem under combat conditions. U.S. forces are conducting offensive strikes while simultaneously defending forces and critical infrastructure against Iranian missile attacks, creating substantial demand for both long-range precision weapons and defensive interceptors.

Patriot PAC-3 Missile Segment Enhancement interceptors are particularly important because they provide U.S. forces with a high-end capability against tactical ballistic missiles and other demanding aerial threats. As the Patriot inventory declines, commanders may have to become increasingly selective about which incoming threats justify expenditure of these advanced interceptors.

CSIS assessed in May 2026 that PAC-3 MSE production was running at approximately 650 interceptors annually, with output supporting both U.S. requirements and international customers. The analysis also cited an Army FY2027 requirement for 3,203 Patriot missiles, while indicating that additional deliveries associated with increased procurement would not begin until 2029.

Those figures expose the central problem behind the U.S. missile shortage. Combat forces can expend interceptors within minutes, while Pentagon missile production and procurement require much longer timelines to restore operational inventories.

This industrial constraint is particularly important as the U.S. Army and its allies continue expanding their Patriot PAC-3 MSE air and missile-defense capabilities. Growing international demand strengthens allied air defense but simultaneously increases pressure on production capacity and specialized suppliers.

Lockheed Martin's PAC-3 Missile Segment Enhancement (MSE) production line. Expanding PAC-3 MSE output has become increasingly important for rebuilding U.S. Patriot interceptor inventories following heavy combat expenditure while maintaining missile-defense readiness for other potential contingencies. (Picture source: Lockheed Martin)

THAAD faces an even more concentrated inventory challenge. The Terminal High Altitude Area Defense system is designed primarily to intercept ballistic missiles during the terminal phase of flight, providing a specialized defensive layer against threats that cannot necessarily be assigned to cheaper short-range weapons.

CSIS estimated in late July that the U.S. THAAD stockpile had fallen to approximately 250 interceptors. The exact operational stock remains classified, and the estimate should therefore not be interpreted as an official Department of Defense inventory figure.

The relationship between the estimated THAAD stockpile and production capacity nevertheless illustrates the endurance problem. CSIS previously assessed surge THAAD production at approximately 96 interceptors annually, while Lockheed Martin was working toward substantially greater manufacturing capacity, potentially reaching 400 interceptors per year.

CSIS also cited a U.S. Army requirement for 857 THAAD interceptors in FY2027, but projected that deliveries would begin only around mid-2029. Under that assessment, replacing missiles expended during the Iran campaign would extend toward the end of 2029.

For operational commanders, shortages begin influencing decisions well before inventories reach zero. Interceptors must support deployed batteries, training, testing and contingency reserves while remaining geographically distributed among several potential theaters.

Every interceptor committed to the Middle East is consequently unavailable for another requirement until industry produces a replacement. This is where the Patriot inventory and THAAD stockpile become strategically relevant to a possible China conflict rather than remaining simply a Pentagon procurement issue.

U.S. missile-defense forces support commitments in Europe, the Middle East and the Indo-Pacific. In the Western Pacific, American and allied installations could face large numbers of ballistic and cruise missiles, making interceptor depth particularly important during the opening phase of a conflict.

The Pentagon would have to decide which bases and operational nodes receive the strongest missile-defense coverage, which threats warrant expenditure of scarce high-end interceptors and how ammunition is distributed across a geographically dispersed theater. Reduced magazine depth could therefore translate directly into greater operational risk even while Patriot and THAAD batteries remain deployed and functional.

The Iran war also demonstrates why layered air defense is becoming essential to preserving high-end interceptors. An adversary combining ballistic missiles, cruise missiles, and unmanned aerial vehicles can attempt to saturate defenses while forcing defenders to consume different categories of ammunition.

A THAAD interceptor launches from the Reagan Test Site at Kwajalein Atoll during Flight Test THAAD-23 on August 30, 2019. Heavy interceptor expenditure during the Iran war has increased pressure on the U.S. THAAD stockpile, raising concerns over missile-defense readiness for another high-intensity contingency. (Picture source: U.S. DoD)

Using an expensive PAC-3 MSE air defense interceptor against every lower-tier aerial threat would rapidly reduce magazine depth. Counter-unmanned aerial systems, electronic warfare, guns, and shorter-range missiles therefore have an additional operational role: preserving advanced interceptors for ballistic missiles and other threats requiring their performance.

The inventory challenge is not limited to defensive weapons. Sustained U.S. strikes against Iran have also generated substantial demand for long-range offensive missiles.

According to the CSIS assessment, more than 1,000 Tomahawk Land Attack Missiles were expended during the Iran conflict. If broadly accurate, that figure demonstrates how rapidly an inventory of long-range cruise missiles can decline when precision strike moves from limited attacks to a sustained campaign.

Tomahawk missiles allow U.S. Navy surface combatants and submarines to attack land targets from extended distances, reducing the immediate requirement to place crewed aircraft inside heavily defended airspace. This makes the missile particularly valuable for attacking command facilities, air-defense infrastructure and other high-value targets during the opening stages of a campaign.

The same characteristics make Tomahawk missiles highly important to U.S. operational planning for a China conflict. The geography of the Western Pacific places a premium on weapons capable of striking at long range while reducing the exposure of aircraft, ships and other launch forces to Chinese anti-access and area-denial capabilities.

Heavy Tomahawk expenditure in the Iran war therefore carries an opportunity cost. A cruise missile used against an Iranian target cannot be available for a Western Pacific contingency until a replacement reaches the U.S. inventory.

CSIS assessed that recent Tomahawk production had remained below 200 missiles annually because previous procurement quantities were comparatively limited, despite industry's ability to expand manufacturing capacity. Under the projected procurement schedule cited by CSIS, missiles associated with the Navy's FY2027 request would not begin entering inventories until around 2030.

The comparison between more than 1,000 estimated Tomahawk missiles expended and recent annual production below 200 illustrates the strategic issue more clearly than procurement totals alone. Sustained combat can consume several years of peacetime output within a much shorter period.

The U.S. Army faces a related challenge with long-range ground fires as it transitions from the Army Tactical Missile System to the Precision Strike Missile. PrSM provides a range exceeding 400 km in its initial configuration, extending Army strike reach beyond the approximately 300 km maximum associated with longer-range ATACMS variants.

The M142 High Mobility Artillery Rocket System and M270A2 Multiple Launch Rocket System can carry two PrSM missiles in a launch pod position that accommodates one ATACMS missile. The combination increases both engagement range and the number of long-range missiles immediately available to a launcher.

This gives the U.S. Army formations the ability to attack command posts, missile units, air-defense sites, logistics facilities, and other high-value targets from greater stand-off distances. As examined in Army Recognition's coverage of the U.S. Army's expanding PrSM long-range precision-strike capability, the missile is becoming a central element of the service's effort to restore operational-level fires against sophisticated adversaries.

That capability has particular relevance in the Indo-Pacific. The U.S. Army long-range fires could contribute to joint operations by attacking high-value targets across maritime approaches and contested areas while complicating an adversary's ability to concentrate missile forces, air defenses and command infrastructure.

PrSM's relatively recent introduction, however, means the Army is building the inventory while simultaneously preparing the missile for operational use. Sustained combat expenditure can therefore place much greater pressure on PrSM than on a weapon accumulated over decades.

CSIS has reported differing indications concerning PrSM expenditure during the Iran conflict, including an account from one Army official suggesting that the available inventory had been expended while other officials indicated that missiles remained.

Without an official Pentagon disclosure, it would be premature to state that the entire U.S. PrSM inventory has been exhausted. The operational lesson remains significant: a relatively small inventory of a newly fielded long-range missile can be consumed rapidly once sustained combat begins.

U.S. NavyUSS Delbert D. Black (DDG 119) fires a Tomahawk Land Attack Missile during Operation Epic Fury on February 28, 2026. Heavy Tomahawk expenditure against Iran is increasing pressure on U.S. missile inventories and future Indo-Pacific readiness. (Picture source: U.S. Navy)

Taken together, Patriot, THAAD, Tomahawk, and PrSM expose different dimensions of the same readiness problem. Patriot and THAAD determine how long U.S. forces can sustain high-end missile defense, while Tomahawk and PrSM contribute to the ability to strike critical targets from stand-off distances.

A two-war scenario would place pressure on both sides simultaneously. U.S. forces could have to continue defending troops and conducting strikes in the Middle East while rapidly shifting additional missile-defense and long-range strike capacity toward the Indo-Pacific.

The challenge would not necessarily be the availability of launchers. Patriot batteries, THAAD launchers, HIMARS, M270A2 launchers, destroyers and submarines could remain operational while declining ammunition inventories reduce the number of engagements they can conduct.

This distinction is fundamental to understanding modern U.S. combat power. Launcher numbers describe potential firepower; missile inventories determine how long that firepower can be sustained.

The Iran campaign is therefore exposing a broader vulnerability in precision warfare. The United States has invested heavily in increasing missile range, accuracy, survivability and seeker performance, but technological superiority does not automatically provide the ammunition mass required for prolonged operations.

The defense industrial base consequently becomes part of the combat equation. Lockheed Martin's role in expanding Patriot PAC-3 MSE, THAAD and PrSM production, together with RTX and other suppliers supporting Tomahawk manufacturing, connects major U.S. defense contractors directly to the Pentagon's ability to restore combat endurance.

Pentagon missile production depends on more than final assembly. Rocket motors, seekers, guidance electronics, warheads, energetics and specialized materials must be available in sufficient quantities, meaning shortages at individual suppliers can constrain the output of complete missiles.

This explains why current Pentagon efforts to expand U.S. missile and ammunition production have strategic importance beyond procurement policy. Manufacturing capacity increasingly determines how rapidly American combat power can regenerate after sustained missile expenditure.

The immediate industrial requirement is therefore straightforward: increase output while shortening the time between congressional funding, Pentagon contracts and deliveries to operational inventories. The objective is not simply to replace weapons fired against Iran, but to build enough reserve depth to absorb future combat expenditure without creating an extended readiness gap.

That requirement returns the debate to the central question: can America fight two missile-intensive wars?

The answer cannot be measured simply by the total size of the U.S. defense budget or the number of aircraft, ships and ground systems available. A second high-intensity conflict would impose enormous ammunition requirements, and the ability to sustain those requirements depends on inventories accumulated before combat begins and production available after expenditure starts.

A China conflict would be particularly demanding because geography magnifies the value of long-range strike and missile defense. U.S. and allied forces would operate across widely separated bases and maritime areas while facing one of the world's largest and most diverse missile arsenals.

Patriot and THAAD could protect selected critical assets, but no missile-defense force can defend every location equally. If interceptor inventories are constrained, commanders would have to prioritize the bases, headquarters and logistics nodes considered most important to sustaining the campaign.

Tomahawk, PrSM and other long-range missiles would face a similar allocation problem. Limited inventories could force commanders to reserve weapons for targets offering the greatest operational effect, potentially reducing the frequency or breadth of strike operations.

The resulting vulnerability does not require American inventories to reach zero. Operational constraints emerge earlier, when commanders must reserve interceptors for the most dangerous threats, narrow offensive target sets, redistribute ammunition between theaters or accept greater risk to assets that cannot receive sufficient protection.

This creates the real second-conflict problem for Washington. The U.S. military can remain capable of sustaining the Iran war while simultaneously reducing the margin available to respond to a rapidly developing crisis involving China.

For deterrence, that distinction is critical. Potential adversaries do not need to believe American missile magazines are empty. Their calculations could change if they assess that U.S. inventories have fallen sufficiently to limit the duration, intensity or geographic scale of an American response.

The Iran strike campaign has consequently become a real-world stress test of American missile endurance. Successful strikes and interceptions demonstrate the effectiveness of U.S. weapons, but every successful engagement also consumes ammunition that the Pentagon and defense industry must replace.

The deeper lesson is that missile scarcity can convert an industrial problem into an operational constraint and eventually into a strategic vulnerability. The relevant metric is no longer simply whether a missile can defeat its intended target, but whether the United States can manufacture and stockpile enough of those missiles to sustain the number of engagements expected in a major war.

For the Pentagon, rebuilding the Patriot inventory, restoring the THAAD stockpile, replenishing Tomahawk missiles and expanding PrSM production therefore form part of the same strategic requirement. The United States must regenerate ammunition consumed in the Iran war without sacrificing the reserve depth needed to deter or fight another adversary.

The principal lesson from the Iran campaign is not that the United States has lost its missile advantage. Patriot, THAAD, Tomahawk and PrSM provide highly capable defensive and offensive effects, but their combat value ultimately depends on sufficient ammunition being available to sustain those effects over time.

If the CSIS inventory estimates and replenishment timelines prove broadly accurate, the Iran war has exposed a consequential gap between the speed at which U.S. forces can expend advanced missiles and the speed at which American industry can replace them. Whether Pentagon missile production can close that gap before another major crisis emerges may become one of the most important measures of U.S. military readiness.

For the United States, the strategic question is therefore no longer only how effectively American missiles performed against Iran. It is whether the United States can rebuild its missile magazines quickly enough to ensure that fighting one war does not reduce its ability to deter, and if necessary fight, a second high-intensity conflict with China in the Indo-Pacific.

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Written by Alain Servaes – Chief Editor, Army Recognition Group
Alain Servaes is a former infantry non-commissioned officer and the founder of Army Recognition. With over 20 years in defense journalism, he provides expert analysis on military equipment, NATO operations, and the global defense industry.