As the war between the United States and Iran stretches into its fifth month, shortages of U.S. missile stockpiles and slow production are emerging as a new strategic burden. Because some key missiles can take up to five years to produce anew, analysts say a prolonged war could increasingly strain military readiness not only in the Middle East but also in other regions such as the Indo-Pacific.
On the 27th (local time), the Wall Street Journal (WSJ) reported that since the war with Iran began on Feb. 28, U.S. forces have used large numbers of offensive missiles to strike targets in Iran and defensive missiles to intercept Iran's ballistic missiles and drones. That has fueled concerns about whether the remaining missile stockpiles alone can sustain the war.
The U.S. government does not disclose missile stockpiles by type, citing the risk that revealing quantities would expose U.S. military vulnerabilities not only to Iran but also to Russia, China and North Korea. Even in peacetime, the U.S. military's ammunition and missile inventories are treated as classified. Instead, officials have stressed that current quantities are sufficient for ongoing operations in Iran. President Donald Trump said the United States has enough missiles, and the White House and the Ministry of National Defense also said they have ample forces to carry out missions ordered by the president.
Still, ramping up missile production in the short term appears difficult. According to the Center for Strategic and International Studies (CSIS), depending on the missile, new production can take three to five years. The White House and the Ministry of National Defense are pressing defense contractors to speed up, but limited supplies of critical components, complex manufacturing, and the time needed to expand facilities and skilled labor mean there are limits to short-term output increases.
CSIS analyzed seven key weapons used during the first 39 days of the Iran war in April and estimated that the U.S. military likely expended more than half of prewar stockpiles for four of the seven. It found that replenishing those inventories to prewar levels would take one to four years, depending on the weapon. In particular, Terminal High Altitude Area Defense (THAAD) interceptor rounds were assessed as among the hardest to quickly replenish if the war escalates or conflict breaks out elsewhere, given limited production, constrained stockpiles and few alternatives.
The pace of weapons consumption in the Middle East is also weighing on U.S. readiness in the Indo-Pacific. In April, the WSJ reported that the United States had used more than 1,000 Tomahawk cruise missiles and 1,500 to 2,000 air-defense interceptors, including THAAD, Patriot and SM-series ship-launched interceptors, in the Iran war, and that fully replenishing them could take up to six years. As the U.S. government recently weighed a large additional strike on Iran, it also examined the impact on stocks of Patriot and other air-defense interceptors, in the same vein. Some government officials were said to worry about constraints on fully executing existing defense plans if a similar crisis, such as a short-term military clash in the Taiwan Strait, were to occur.
CSIS believes the United States currently has sufficient missile and weapons stocks to continue the Iran war. Still, the time needed to replenish inventories consumed in the Middle East poses a risk that gaps could open in readiness if military conflict erupts in other regions such as the Western Pacific. The longer the U.S.-Iran military confrontation drags on, the greater the burden on the United States to expand missile production and manage stockpiles to sustain Middle East operations while maintaining Indo-Pacific readiness.