WASHINGTON (Realist English). The United States will need at least three years to restore stocks of critical weapons systems after its 38-day bombing campaign against Iran, according to a new analytical report by the Center for Strategic and International Studies (CSIS), published on May 27.
The depletion of inventories has created a “window of vulnerability for a potential conflict in the Western Pacific,” the authors warn. The time needed to rebuild the arsenals has become a major concern. At the same time, the analysts acknowledge that the US “had enough munitions for any plausible scenario in the Iran war.”
Scale of Expenditure
US Central Command reported that more than 12,000 targets were struck during Operation Epic Fury. According to CSIS estimates, this led to a significant reduction in American stockpiles:
- Tomahawk Land Attack Missiles (TLAM): More than 1,000 missiles were used, far exceeding the average annual procurement of 86 over the past decade. Replenishment could take until 2030–2031.
- THAAD interceptors (Terminal High Altitude Area Defense): Up to 290 missiles were used. Reserves are not expected to return to previous levels until the second half of 2029.
- Patriot interceptor missiles: Stockpiles were also significantly depleted.
The Pentagon did not disclose the exact scale of munitions used before the ceasefire with Tehran took effect on April 7, citing operational security. However, Acting Pentagon Comptroller Jules Hurst told lawmakers earlier this month that the conflict had cost roughly $29 billion, with additional expenditures still expected.
“The Problem Is Not Money, but Time”
The authors of the report emphasise that the main challenge is not financing, but time.
“It takes time to expand production capacity and to build these complex systems. Thus, there will be a window of vulnerability for several years until inventories return to their previous levels and another several years before they get to the levels that war planners desire,” the analysts wrote.
The report also notes that China “is deeply aware that it has no recent combat experience and that it performed poorly in its last war — against Vietnam in 1979.” According to CSIS, this difference in experience may preserve deterrence until US munitions inventories are restored.
Response from the White House and Pentagon
White House Deputy Press Secretary Anna Kelly told Military Times that the US military “has more than enough munitions, ammunition and stockpiles to serve all of President Trump’s strategic goals and beyond.”
“Even still, the president has urged our defence contractors to constantly produce more made-in-America weapons, which are the best in the world. Democrats destroyed our military, but President Trump rebuilt it. Think tank armchair quarterbacks are not read into sensitive information and have no idea what they’re talking about,” she added.
Trump recently met with executives from major defence contractors — including BAE Systems, Boeing, Honeywell Aerospace, L3Harris Missile Solutions, Lockheed Martin, Northrop Grumman and Raytheon — to discuss expanding production capacity. Following the meeting, the president announced that the CEOs “agreed to quadruple production of the ‘Exquisite Class’ weaponry in order to reach, as rapidly as possible, the highest levels of output.”
Defence Secretary Pete Hegseth, who has acknowledged that replenishing the Pentagon’s arsenal will take “months and years” depending on the system, stressed on May 27 that the process is already underway.
“Defence manufacturers are investing in new plants, new manufacturing facilities and new production lines, so that we’re getting weapons faster than ever,” Hegseth said during a cabinet meeting at the White House.
Budgetary Consequences and Funding Shortfalls
According to CNN, citing sources, infrastructure repairs alone could push the final cost of the conflict to $40–50 billion.
The replenishment of arsenals is complicated not only by the high rate of expenditure, but also by rising weapons costs. Budget expert Linda Bilmes notes that replacing a single Tomahawk cruise missile now costs $3–3.5 million, whereas its official cost had previously been estimated at about $2 million.
The war with Iran, which was not funded in the Pentagon’s original 2026 budget, is placing direct pressure on current military spending.
- Training programme cuts: To cover operational expenses, the military has been forced to reallocate funds, leading to serious reductions. For example, the training budget for the US Army’s III Armored Corps was cut by nearly $292 million.
- Reduced flight hours and recruitment: Chief of Naval Operations Admiral Daryl Caudle stated that his budget “did not account for Operation Epic Fury,” leading to restrictions on exercises, flight training and even the recruitment of new personnel. Other branches of the armed forces are facing similar problems.