In a high-profile appearance earlier this month at the Pennsylvania Defense and Innovation Summit, U.S. President Donald Trump stood alongside chief executives of the nation’s largest defense contractors and delivered a clear, urgent call: ramp up weapons production and accelerate manufacturing timelines to rebuild dwindling stockpiles.
Addressing a gathering of arms industry leaders at the U.S. Army War College, with Secretary of Defense Pete Hegseth at his side, Trump emphasized, “We have the best quality in the world, but we need a little more speed.” The Trump administration framed the summit as a core component of a dual strategy to rejuvenate domestic defense manufacturing and strengthen the country’s warfighting capacity, what Hegseth has called America’s “arsenal of freedom.”
What went largely unmentioned during the summit, however, is the core driver of this new push: massive stockpile depletion from nearly 40 days of intense combat during this year’s Operation Epic Fury in Iran, paired with ongoing tit-for-tat cross-border strikes in the region. To date, the U.S. government pegs total war costs at $37.5 billion, the vast majority of which has gone toward expended munitions. By the time a fragile ceasefire took hold on April 8, U.S. forces had struck more than 13,000 targets across Iran and intercepted more than 1,700 Iranian drones and ballistic missiles, White House data shows.
Today, U.S. offensive strikes against Iran are paused to allow diplomatic negotiations to proceed. A recent New York Times report revealed that Trump’s military advisors urged him to abandon plans for conflict escalation, warning that further action would only deepen stockpile shortfalls. The president has pushed back on these concerns, telling The Wall Street Journal, “We have far more munitions than anyone in the world, and far more than we need.”
The issue of depleted stockpiles has been a point of internal tension within the administration for months. Last month, Hegseth rejected claims that supplies were running low. But his position shifted dramatically last week, when he told the Senate Appropriations Committee the Pentagon requires an additional $87 billion to address “critical shortfalls” in equipment and munitions.
While exact figures for expenditure and remaining stockpiles remain classified, publicly available analysis from the Center for Strategic and International Studies (CSIS), a Washington D.C.-based think tank, outlines a stark landscape of depleted inventories that cannot be quickly replenished. “It depends on the munition, but one to five years [to manufacture a single advanced missile] is the bottom line,” explained Mark Cancian, a retired Marine Corps colonel and senior CSIS adviser who researches defense stockpiles. “And there’s nothing you can do to speed that up.”
The munitions most heavily drawn down during the Iran conflict fall into two critical categories: long-range land-attack systems and air and missile defense interceptors used to neutralize incoming Iranian attacks. The most widely used offensive weapon was the Tomahawk Land Attack Missile (TLAM), a sea-launched precision weapon capable of striking targets more than 1,000 miles inland, allowing the U.S. to destroy hardened military sites like command bunkers without risking manned aircraft. CSIS estimates more than 1,000 Tomahawks were fired during the operation, and stockpiles may not return to pre-war levels until 2031. Each new TLAM variant costs approximately $2.6 million.
On the defense side, the Patriot interceptor — a ground-based missile designed to shoot down aircraft, ballistic missiles and cruise missiles — saw the heaviest use. CSIS estimates that as many as 1,430 Patriots were fired during the conflict, drawn from a pre-war stock of roughly 2,330. Each Patriot interceptor costs around $4 million, a steep price to pay to shoot down low-cost Iranian drones that only cost between $20,000 and $50,000 apiece. Like Tomahawks, Patriots require years to replace: “If you put funding into production today, you wouldn’t take delivery of finished missiles for three or four years. Sometimes even five,” Cancian said, noting that current deliveries are for missiles funded back in 2023.
The more advanced Terminal High Altitude Area Defense (THAAD) system, which offers longer range and higher-altitude intercept capabilities than the Patriot, was also deployed. Pre-war stockpiles of THAAD interceptors were already limited, with CSIS estimating that 190 to 290 interceptors were fired from a pre-war total of 360. Only nine THAAD batteries exist globally, seven of which are operated by the U.S. Sustained expenditure leaves open the risk that U.S. forces could lack this critical capability for defending against ballistic missile threats from major powers like Russia, China, or North Korea.
This depletion comes at a particularly sensitive geopolitical moment, ahead of the so-called “Davidson window” — a timeframe when many U.S. military planners assess that China is more likely to move to take control of self-governing Taiwan, which Beijing claims as a breakaway province. The concept originated from a 2021 congressional hearing where then-Indo-Pacific commander Admiral Philip Davidson warned a Chinese invasion could come “within six years,” and then-CIA Director William Burns echoed the assessment in 2023, predicting China would be militarily prepared by 2027.
Cancian warns that current stockpile shortfalls create a “window of vulnerability” that leaves the U.S. without the full inventory of preferred munitions it would need for a large-scale Pacific conflict. This unpreparedness, he argues, increases the risk that U.S. forces would be outmatched by China’s massive arsenal of advanced missiles and aircraft. U.S. officials note China has closely studied U.S. air defense operations during the Iran conflict, and has invested heavily in advanced missile technology including hypersonic glide vehicles far more capable than Iran’s conventional missiles and low-cost drones, alongside developing large-scale drone swarm tactics.
Not all analysts frame depleted stockpiles as a pure liability, however. Jacob Olidort, a former CIA analyst and former Middle East policy adviser at the Pentagon, argues that the use of these weapons in combat sends a powerful deterrent signal. “Weapons create deterrence, not merely because nations have them, but also because they demonstrate a willingness to use them,” said Olidort, now director for American security policy at the America First Policy Institute. He added that the U.S. campaign’s success in eroding Iran’s military capabilities in a compressed timeframe sends a clear message to other adversaries, including China, about American military prowess.
The tension between preserving U.S. stockpiles and supplying allied nations already played out publicly ahead of the Iran conflict, when Trump rejected Ukrainian requests for Tomahawk missiles in October 2025, citing the need to protect U.S. reserve inventories. That episode previewed the difficult trade-offs now shaping debate over U.S. global military posture. Ukrainian President Volodymyr Zelensky told the BBC in March that the Iran conflict has exacerbated critical weapons shortages for his country, which is facing relentless Russian drone and missile strikes and urgently needs additional Patriot air defense systems.
Zelensky outlined the stark mismatch between production and demand: the U.S. produces roughly 60 to 65 Patriot missiles per month, or 700 to 800 per year — and 803 Patriots were expended on the first day of Operation Epic Fury alone. More recently, Trump surprised European officials by announcing a deal that would allow Ukraine to produce Patriot missiles domestically, a licensing arrangement already in place with Germany and Japan.
Some defense analysts see the dual lessons from Ukraine’s war against Russia and the U.S. campaign against Iran as a catalyst for rethinking how the U.S. designs and produces air defense systems. Elaine McCusker, a 13-year veteran of the Pentagon who now works as an expert at the American Enterprise Institute, said these experiences could drive development of cheaper, mass-produced alternatives to complement high-cost advanced interceptors. “We’ve known for a long time that we don’t want to be shooting $6 million interceptors at $1,000 drones,” she said. “I think we now have more focus on that solution, and more people focusing on manufacturing more attritable solutions that don’t cost so much.”
Even with significant stockpile drawdowns, there is little immediate concern that the U.S. would run out of munitions if the Iran ceasefire collapses — not because U.S. stockpiles are unlimited, but because Iran’s stockpiles and production capacity are in far worse shape. “The United States military has more than enough munitions, ammo, and stockpiles to serve all of President Trump’s strategic goals and beyond, and Operation Epic Fury has exposed what happens when you mess with the United States,” White House spokesperson Anna Kelly said in a statement. “Even still, the president has urged our defence contractors to constantly produce more made-in-America weapons.”
Recent U.S. strikes carried out by Central Command have focused heavily on degrading Iran’s ability to disrupt shipping in the Strait of Hormuz, the vital global oil shipping lane that has seen repeated blockades by both sides. After waves of U.S. and Israeli strikes, Iran’s military losses far outpace American losses, and the country has almost no ability to quickly replenish its lost weapons systems. “A lot of commentary portrays Iran as having an almost unlimited amount of weaponry,” said Jason Brodsky, policy director of United Against Nuclear Iran. “I think we have to realise that there are limitations there, and that the U.S. has degraded their defence industrial base to a very significant extent.” Brodsky added that Iran’s capacity to mass-produce missiles, drones and other critical weapons has been largely destroyed.
Brodsky noted that Iran’s remaining stockpiles are now concentrated almost entirely on its ability to threaten shipping through the Strait of Hormuz, a capability that is rapidly fading. “The Iranian regime is running out of time here,” he said. For the Biden administration, the ongoing, manageable conflict with Iran remains the immediate priority, even as officials acknowledge that ignoring long-term stockpile challenges would be irresponsible. “The Indo-Pacific is a more distant threat right now,” Brodsky said. “Policymakers have to prioritise, and the Middle East right now has the president’s attention.”
For now, every missile fired against Iranian targets, delivered to Ukrainian frontlines, or held in reserve for a potential Taiwan conflict draws from a steadily shrinking national inventory. The U.S. is betting that it can manage current commitments while defense manufacturers ramp up production to replenish stockpiles over the coming years.