US Precision Strike Inventory Depletion: CSIS Assessment of Operation Epic Fury Munitions Expenditure

Technical Summary

A Centre for Strategic and International Studies (CSIS) analysis published on 21 April 2026 quantifies United States precision strike munitions expenditure during Operation Epic Fury, the 39-day air and maritime campaign against Iranian nuclear and military infrastructure. The report concludes that the United States prosecuted more than 13,000 aim points over the course of the conflict. For four of the seven key munitions assessed, expenditure exceeded 50% of prewar stockpile levels, with rebuild-to-baseline timelines estimated at one to four years depending on current production rates.

Munition types assessed include the BGM-109 Tomahawk Land Attack Missile (TLAM), the Patriot GEM-T (Guidance Enhanced Missile – Tactical) interceptor, the Terminal High Altitude Area Defense (THAAD) interceptor, and the Precision Strike Missile (PrSM). All figures derive from open-source FY 2026 budget documentation and Congressional testimony; they represent estimates rather than certified inventory figures.

Analysis of Effects

The BGM-109 Tomahawk TLAM presents the most significant near-term rebuild challenge. Following a production hiatus of approximately a decade prior to the 2023 re-award to Raytheon (RTX), the current production line is operating at a rate insufficient to restore pre-conflict inventory within a two-year window. RTX confirmed an accelerated production increment in response to Epic Fury depletion, but facility throughput constraints at the Tucson, Arizona manufacturing site point toward a three-to-four-year rebuild timeline based on available contracting data.

Patriot GEM-T and THAAD interceptors were already under dual-drawdown pressure prior to Epic Fury, with significant quantities transferred to Ukraine and European North Atlantic Treaty Organisation (NATO) allies under foreign military sales (FMS) mechanisms between 2022 and 2025. Additional consumption during Epic Fury compounds a pre-existing shortfall and directly reduces the United States capacity to supply further interceptors to allies — a direct constraint on NATO ballistic missile defence (BMD) architecture in the European theatre.

PrSM, the successor to the Army Tactical Missile System (ATACMS), entered operational service in limited numbers only in 2023. Its prewar stockpile was therefore modest by design. Any consumption exceeding planned operational reserves creates an amplified percentage-depletion figure. Industrial base ramp-up, rather than drawdown management, is the primary remediation lever for this system. The CSIS analysis also notes diminished inventories will affect US supply of Patriot, THAAD, and PrSM to Ukraine and other allies, with cascading implications for extended deterrence commitments.

Personnel and Safety Considerations

From a WOME practitioner standpoint, the policy implications of precision munitions depletion cascade into several operational domains. Ammunition Technical Officers (ATOs) and Weapons Technical Intelligence (WTI) practitioners advising procurement authorities should note that the current depletion pattern creates an environment in which allied nations may seek alternative precision strike solutions from non-NATO-standard suppliers. Due diligence on technical standards, fuze reliability, explosive fill specifications, and storage compatibility becomes correspondingly more important when supply chains diverge from established Allied Quality Assurance Publication (AQAP) qualification routes.

The CSIS report specifically flags the risk to peer-competitor contingencies, most plausibly a Taiwan Strait scenario. Ammunition planners within NATO and Five Eyes defence establishments should factor the reduced US magazine depth into campaign analysis and escalation modelling. The assumption that US strategic reserve stocks will be available for coalition burden-sharing in a simultaneous or near-simultaneous contingency cannot be sustained without explicit post-Epic Fury restocking commitments.

Data Gaps

DATA GAP: Exact prewar inventory figures for each munition type remain classified; CSIS estimates carry inherent uncertainty derived from budget documentation. DATA GAP: Post-ceasefire restocking contract values and delivery schedules have not been publicly confirmed in full. DATA GAP: The classified CSIS annex covering additional strike systems is not available for open-source review. DATA GAP: Specific impact on NATO allies Patriot and THAAD interceptor allocation queues has not been officially quantified by SHAPE or SACEUR.

AI-assisted technical assessment based on open-source material (CSIS, April 2026). Not a formal intelligence product. All figures are derived from publicly available FY 2026 budget documentation and open-source analysis.