By Mark Temnycky
As the U.S. war with Iran enters its seventh month, the U.S. military "has depleted much of its global stockpile of highly accurate long-range missiles," Reuters reported. Throughout the war, the U.S. has used weapons such as Army Tactical Missile Systems and Precision Strike Missiles to strike targets in Iran, as well as Patriot and THAAD anti-ballistic systems to defend against Iranian attacks. Due to the continued use of these weapons throughout the war, Reuters reported that U.S. stockpiles of defensive weapons were "dwindling."
The Center for Strategic and International Studies further contributed to these findings. In a report published on July 27, CSIS tracked data on stockpiles of Patriot missiles and THAAD interceptors throughout the war. In its assessment of the situation, CSIS wrote that the US had 2,330 Patriot missiles and 452 THAAD interceptors on February 27. However, by July 27, CSIS estimated that the U.S. stockpile of Patriot missiles had dropped from 2.330 on February 27 to between 759 and 827. Similarly, CSIS estimated that THAAD interceptors had decreased from 452 on February 27 to between 234 and 278 on July 27.
U.S. President Donald Trump dismissed reports of a decline in U.S. stockpiles, arguing that "the U.S. has vast amounts of 'ammunition,' particularly of certain types." He added that "large quantities are manufactured and shipped to the US when needed".
Similarly, U.S. Secretary of Defense Pete Hegseth rejected claims that U.S. stockpiles have declined. When asked if the US is facing a crisis in ammunition stockpiles, Hegseth said it was a "fabricated story". He added that "America's reserves are excellent and constantly strengthening."
The debate over U.S. munitions and stockpiles has forced defense companies, policymakers, and defense experts to rethink how U.S. weapons are produced. After the end of the Cold War, ammunition supplies to the United States began to shrink. Some manufacturers closed, as large-scale defense production was no longer necessary. Keeping production lines running was also costly. In addition, a report published by the US Department of Defense found that the "number of companies in the defense industrial base shrank dramatically" as the defense sector moved "from 51 to 5 major aerospace and defense contractors."
"When the Cold War ended, the United States changed its expectation from a war between great powers to brief regional wars against adversaries such as Iraq or North Korea. This did not require a large stockpile of ammunition. As a result, stockpiles declined," Mark Cancian, Senior Advisor in the Defense and Security Division of the Center for Strategic and International Studies, said in an interview.
But when Russia launched its full-scale invasion of Ukraine on February 24, 2022, and when the US war with Iran began on February 28, 2026, this led to increased demand for Western weapons. The need for these weapons and their use have far exceeded supply and production. As a result, this has put a strain on the defense industrial base.
"The fundamental challenge with today's ammunition, such as the Tomahawk and the Patriot, is that these are really very good systems and they have proven themselves in practice. They were designed a long time ago and were designed primarily with performance in mind. They were not designed with the possibility of mass production in mind, so that they can be produced on a large scale," said Dr. Jerry McGinn, Director of the Center for the Industrial Base at the Center for Strategic and International Studies.
It takes time to produce these sophisticated weapons. According to a report published by The Hill, it will take "at least a few years" for the US to replenish its reserves to pre-war levels with Iran. Why is this happening?
"If you want more production capacity, you have to create it," McGinn explained during our conversation. "Its creation takes time. You need licenses and approvals, then you need to build and certify it. In this case, it is difficult to accelerate the rate at which they are produced."
Cancian noted that today's deliveries were funded in 2023 and 2024. Regarding the U.S. THAAD stock, CSIS found that previous fiscal documents had predicted zero deliveries between August 2023 and April 2027. The CSIS report added that deliveries appear to have been rescheduled, likely by diverting systems from allies, given the increased demand and need for these systems. The Trump administration's budget for fiscal year 2027, if approved, provides for $11 billion for THAADs, but deliveries will not begin until mid-2029. The CSIS report adds that deliveries will "complete the replacement of use during the war with Iran" by "the end of the 2029 calendar year."
CSIS found the same for Patriot deliveries. The fiscal year 2027 procurement will begin deliveries in May 2029, and Cancian told me that pre-war Patriot stock levels will not be reached before 2030. In other words, it will take more than three years before new deliveries restore stocks to pre-war levels. Meanwhile, Russia's full-scale invasion of Ukraine and the U.S. war with Iran continue and may require more missiles.
"The biggest problem concerns the shortcomings in missile defense, Patriot and THAAD, because there are no good substitutes," Cancian said. He also noted that there has been a change in what limits U.S. defense production.
"For a long time, the constraint was funding because ammunition was lower on the list of priorities and competed with a lower chance of success for resources during the Pentagon's budgeting process," Cancian explained. "The Biden administration began to increase funding, and the Trump administration accelerated that effort. Now, the limitation is production capacity. This is growing, but it takes time to hire new workers, build new factories and buy machinery."
However, there are some ways to deal with these time constraints. For example, the US has announced plans to build new factories with the aim of increasing production. The US military began work on the construction of a demilitarization facility in Oklahoma in March, and in July began work on the construction of an ammunition production facility in Iowa. Accordingly, the US military inaugurated a new artillery ammunition production plant in Kansas in April. Although it will take time for these facilities to start producing new defense equipment and weapons, their creation will allow the US to increase its production capacity.
The Trump administration has also called on its NATO allies to greater burden-sharing, a term that refers to a fair distribution of costs, tasks and responsibilities. Following the conclusion of the 2026 NATO Summit in July, the White House published a fact sheet in which it stated that the Alliance has moved "towards greater burden-sharing and greater autonomy". If these discussions materialize, arms cogeneration, particularly abroad, could help increase production capacity. While this will reduce pressure on the U.S. to produce new and existing weapons, it will also take time to achieve these goals.
Overall, Russia's full-scale invasion of Ukraine and the U.S. war with Iran have sparked debate among defense companies, policymakers, and defense experts about the defense industrial base. In its current state, it was not designed to maintain this level of demand for weapons systems. It also seems that the time required to manufacture these weapons is the most urgent issue. Industry leaders will continue to consider ways to reduce production times without sacrificing the quality or reliability of these sophisticated weapon systems.
Forbes
