"The U.S. used so many key offensive and defensive weapons that it will take three or more years to rebuild some of these stocks to pre‑war levels."
Tomahawks: a third of an estimated inventory expended, production lagging
CSIS researchers Mark F. Cancian and Chris H. Park estimated that U.S. forces began Operation Epic Fury with roughly 3,100 Tomahawk Land Attack Missiles (TLAMs) and fired more than 1,000 during the 39‑day war with Iran. The think tank said it based its estimates on Fiscal Year 2027 Pentagon budget documents; TWZ could not independently verify the internal analysis CSIS used to derive those expenditure figures.
Production will not close that gap quickly. CSIS noted Tomahawk procurement averaged 86 missiles per year over FY 2015–FY 2026 because of small past orders, and while Raytheon has a goal of producing more than 1,000 missiles per year, recent annual output has been less than 200. CSIS also flagged nearly 800 Tomahawks promised via foreign military sales to Japan, Australia and the Netherlands, further drawing on available supply.
THAAD and Patriot: magazine depth strained, replacement timelines measured in years
CSIS estimated the U.S. had about 400 Terminal High Altitude Area Defense (THAAD) interceptors before the war and used between 190 and 290 during the conflict; separate reporting cited about 200 THAAD interceptors deployed defending Israel. The Army has requested 857 THAAD interceptors in its FY 2027 budget, with deliveries projected to start in mid‑2029 and to complete replacement of Iran War usage by the end of calendar year 2029. CSIS concluded current THAAD production is at a surge rate of roughly 96 interceptors per year and that Lockheed Martin plans to expand capacity to 400 per year with additional facilities and tooling.
Patriot inventories were similarly affected. CSIS estimated about 2,500 Patriot interceptors in U.S. stocks at the start of the war and that between 1,060 and 1,430 Patriots were fired during Epic Fury. CSIS said PAC‑3 MSE production was around a baseline rate of 650 interceptors per year, with half delivered to the United States and the rest to allies. Lockheed, under a January contract with the Pentagon, has committed to boosting Patriot annual production to 2,000. CSIS cautioned that U.S. procurement averaged only 225 missiles per year in the past decade and that the Army’s FY 2027 request for 3,203 Patriot missiles — projected to start delivery in May 2029 — will be needed to fully restore inventories.
SM‑3 and SM‑6: successful employment, slow replenishment
According to CSIS, the Navy entered Epic Fury with roughly 400 SM‑3 interceptors and had used upwards of about 250, while roughly 1,250 SM‑6 missiles were on hand and between 190 and 370 were launched. The think tank estimated replenishment to pre‑war levels would take about two years, noting both missiles have lengthy production lead times.
The FY 2027 budget requests cited by CSIS include 78 SM‑3 Block IBs, 136 SM‑3 Block IIAs, and 540 SM‑6s, but CSIS warned those orders "will take between 36 and 39 months to begin deliveries once Congress provides appropriations." Because past orders were small, CSIS concluded inventories will not return to pre‑war levels until early 2029 despite what it characterized as relatively low usage in the campaign.
JASSM and PrSM: one‑time uses and scaling plans
CSIS estimated the U.S. had more than 4,000 Joint Air‑to‑Surface Standoff Missiles (JASSMs) before the war and that more than 1,100 were expended. But CSIS said JASSM recovery should be relatively swift: the Air Force has procured large quantities—on average nearly 500 a year for the past decade—and "current production appears to be already at the surge rate."
The Precision Strike Missile (PrSM), a newer ground‑launched system with deliveries beginning in 2023, had an estimated inventory of fewer than 100 prior to Epic Fury and CSIS estimated between 40 and 70 were used. CSIS reported Lockheed Martin has been scaling up PrSM production, setting an annual target of 400 units and announcing further increases under a framework agreement with the Trump administration.
Operational consequences: the Pentagon, paused sales to Taiwan, and continued kinetic exchanges
The Pentagon pushed back on the notion of a critical shortfall. Pentagon spokesman Sean Parnell told TWZ: "America’s military is the most powerful in the world and has everything it needs to execute at the time and place of the president’s choosing. We have executed multiple successful operations across combatant commands while ensuring the U.S. military possesses a deep arsenal of capabilities to protect our people and our interests."
But the operational ripple effects are visible. Acting Navy Secretary Hung Cao testified to the Senate that the U.S. is pausing arms sales to Taiwan "in order to make sure we have the munitions we need for Epic Fury," a step CSIS and TWZ linked back to magazine‑depth concerns driven by the Iran war. TWZ also reported deferred or slowed deliveries to other allied customers.
That strain persists amid intermittent kinetic exchanges: a U.S. official told TWZ that CENTCOM shot down four Iranian drones and struck a ground control station in Bandar Abbas on May 28, 2026, and CENTCOM reported Kuwaiti forces intercepted a ballistic missile Iran launched toward Kuwait that same day. CSIS noted the president’s $1.5 trillion FY 2027 defense budget "reflects these magazine depth concerns," and said a war supplemental for additional munitions funds is expected as DOD seeks to replace what was expended and then build inventories above pre‑war levels.
What this means for the Pentagon, Lockheed Martin, and allied customers
- Pentagon: must balance ongoing operations with planned procurement timelines; CSIS flagged delivery schedules that often do not begin until mid‑2029 or later and warned inventories may not be restored until 2029 for several classes of missiles.
- Lockheed Martin and Raytheon: face pressure to expand production — Lockheed aims to lift THAAD and Patriot outputs and Lockheed’s PrSM targets aim for 400 a year; Raytheon has a stated goal of producing more than 1,000 Tomahawks per year but recent rates remain below 200.
- Allied customers (Japan, Australia, the Netherlands, Taiwan, Ukraine, Israel, Kuwait): deliveries to partners are already affecting U.S. stock levels and, per CSIS and testimony cited by TWZ, shipments have been paused or deferred in some cases while U.S. forces replenish and re‑prioritize munitions.
CSIS’s assessment makes concrete the arithmetic of munitions in modern conflict: high‑intensity use can exhaust inventories faster than industrial base expansion can restore them. The FY 2027 budget requests and framework agreements with industry are intended to speed replenishment, but CSIS’s timeline estimates — deliveries beginning in 2029 for many systems and inventories not fully restored until 2029 or later — leave a measurable window during which policymakers and commanders must weigh risks, operational needs, and the pace of industrial ramp‑up.
