CSIS: US Precision Munitions Stockpile Rebuild a Multi-Year Project After Iran War

Technical Summary

The Center for Strategic and International Studies (CSIS) published an assessment on 27 May 2026 concluding that four classes of US precision-guided munition (PGM) and interceptor expended during Operation Epic Fury, the 39-day US–Israeli air campaign against Iran, will require three or more years to return to pre-war inventory levels. The four classes identified are the BGM/RGM-109 Tomahawk Land Attack Missile (TLAM); the Terminal High Altitude Area Defense (THAAD) interceptor; the MIM-104 Patriot family (PAC-2 GEM-T and PAC-3 MSE); and the Standard Missile series SM-3 (Block IB/IIA exo-atmospheric kinetic kill) and SM-6 (Block IA dual-mode air defence and anti-ship).

CSIS estimates more than 1,000 TLAM all-up rounds were launched during the campaign, an expenditure rate exceeding the ten-year mean US procurement of 86 missiles per year by an order of magnitude. Recapitalisation to pre-war inventory is assessed as unachievable before 2030–2031 at the current Tactical Tomahawk Weapon Control System (TTWCS) Block V Raytheon production cadence. Up to 290 THAAD all-up rounds are reported expended, with stockpile recovery projected to mid-to-late 2029 even after Lockheed Martin's announced production-rate increase from 96 to 400 interceptors per annum under the Trump multi-year framework. Patriot interceptor inventory is reported at approximately 50 per cent of pre-war levels.

Analysis of Effects

The CSIS finding is significant for three WOME-adjacent reasons. First, the figures expose the production-versus-expenditure asymmetry that has been a recurring theme in the post-2022 European procurement debate, but now expressed in US precision munitions terms rather than 155mm conventional artillery. The TLAM example, 1,000-plus launches against an 86-per-year baseline, is a roughly 12:1 expenditure-to-production ratio over the campaign window. Second, the reported FY27 munitions budget request of approximately US$70 billion, a near-threefold increase on current levels, signals that recapitalisation will be funded but constrained by industrial throughput rather than appropriation. Third, the ‘window of vulnerability’ framing, explicitly tied by CSIS to a potential Western Pacific contingency, will shape the Munitions Acceleration Council (MAC) priority list and the multi-year procurement structures issued through OSD-A&S.

For inventory and safety case authors, the assessment is also an indirect signal on the Hazard Division (HD) 1.1 and HD 1.2 storage burden across CONUS Ammunition Storage Areas and forward-deployed Theater Reserves. A near-threefold increase in delivered Net Explosive Quantity (NEQ) over a five-year horizon will require licensed storage capacity to keep pace, and the Quantity Distance (QD) implications at receiving Port-Side Explosive Storage (PES) locations are not addressed in the open report.

Personnel and Safety Considerations

Ammunition technicians, ordnance engineers and munitions accountants in the AUKUS partner inventories should treat the CSIS figures as a baseline assumption for joint stockpile planning. The Royal Australian Navy SM-2/SM-6 and Royal Navy Sea Viper/Aster fleets do not draw from the same production lines, but the THAAD-adjacent UK/AUS air and missile defence requirement (currently in concept phase) competes with US recapitalisation for Lockheed Martin Camden, Arkansas, capacity. Inspectors and Type Qualification authorities should anticipate accelerated Lot Acceptance Test (LAT) and surveillance throughput as production rates climb to the announced ceilings, with attendant pressure on Department of Defense Explosives Safety Board (DDESB) staffing and the corresponding UK Defence Ordnance Safety Group (DOSG) safety case turnaround.

Data Gaps

DATA GAP: Exact split between TLAM Block IV and Block V expenditure not disclosed. DATA GAP: SM-3 Block IIA expenditure figure not separately reported from SM-3 Block IB. DATA GAP: Patriot expenditure split between PAC-2 GEM-T and PAC-3 MSE not stated; HD/CG of all-up rounds not addressed. DATA GAP: Whether the CSIS figures include allied transfers to Israel under existing FMS cases or only US-organic expenditure. DATA GAP: Industrial base bottleneck identification, energetic fill (HMX, RDX, IMX-104), solid rocket motor casing, or seeker/guidance section, not separately attributed. DATA GAP: Receiving-end ammunition storage and QD implications of FY27–FY31 recapitalisation not assessed in open source.

AI-assisted technical assessment based on open-source material. Not a formal intelligence product.