The dwindling stockpiles of defensive interceptors and long-range missiles have become a pressure point for top military and civilian leaders who are weighing the demands of the war with Iran against maintaining readiness to deter other adversaries, including China. The U.S. officials, who spoke to CBS News on condition of anonymity given the sensitivity of the topic, said the U.S. cannot sustain the rate at which it expended precision munitions early in the campaign against Iran. The defense industrial base is not equipped to produce missiles rapidly enough to replenish munitions that have been fired or transferred to U.S. Central Command, which is overseeing the conflict, leaving inventories under mounting pressure even as military operations continue. Interceptors are in heavy use to defend U.S. interests in the Gulf states, which house U.S. troops and are being targeted by Iranian drones and missiles. One partner country told CBS News there is a need for a pause in fighting, particularly given the intensity of Iranian strikes that have been battering Kuwait and Bahrain. Kuwait said earlier this week that Iran struck its infrastructure, damaging electricity and desalination plants. In an interview last month with "Face the Nation with Margaret Brennan," Defense Secretary Pete Hegseth denied that there was any crisis with the stockpiles. He conceded that some munitions may take more time to produce than others, but he told Brennan, "We've got lots of them, we're building more than ever before." "Our stockpiles are strong, and they will only get stronger in the future," Hegseth said.

But U.S. commanders have increasingly been shifting toward using more GPS-guided bombs fitted with Joint Direct Attack Munitions, or JDAM, guidance kits, along with Small Diameter Bombs, which are precision-glide weapons that can attack fixed targets at shorter ranges and can also be used in lieu of long-range standoff weapons. Earlier in the conflict, U.S. forces frequently employed long-range cruise missiles such as the Joint Air-to-Surface Standoff Missile, known as JASSM, and the Tomahawk Land Attack Missile. Those weapons remain in the arsenal, officials said, but are being used more sparingly. In April, Adm. Samuel Paparo, the head of U.S. Indo-Pacific Command, told lawmakers on Capitol Hill that scaling up output of high-end systems such as the Tomahawk cruise missile or JASSM could take years, as defense companies work on expanding production lines. "I think it will take one to two years for them to scale," said Paparo, whose responsibilities include preparing for any potential conflict in the Pacific region, including with China. "It won't be soon enough. There are finite limits to the magazine, and I have all the faith in the world that they're being employed judiciously."

judiciously

Following the collapse of the ceasefire earlier this month, U.S. strikes have focused on targets closer to Iran's coastline, reducing the need for aircraft to penetrate deeper into Iranian territory, where they would face denser air-defense networks and a greater threat from surface-to-air missiles. The U.S. officials told CBS News there are limited inventories of the Army Tactical Missile System, or ATACMS, the long-range missiles fired from the High Mobility Artillery Rocket System, known as HIMARS, a truck-mounted launcher capable of firing precision rockets and missiles. Concerns over certain munition inventories are not new. The Biden administration delayed giving ATACMS to Ukraine in part because drawing from those inventories could undermine U.S. military readiness, CBS News previously reported. The U.S. has comparatively healthier supplies of the shorter-range Guided Multiple Launch Rocket System, or GMLRS, which is also fired from the HIMARS launcher, the officials told CBS News, allowing commanders greater flexibility for targets within its range. The most pressing concern involves air-defense interceptors, used to defend against cruise and ballistic missiles, aircraft and lethal drones, several sources said. The U.S. has expended large numbers of Patriot and Terminal High Altitude Area Defense, or THAAD, interceptors to defend against both ballistic missiles and drones, consuming inventories faster than industry can replace them. To support operations in the Middle East, the Pentagon has shifted interceptor inventories from other regions, including stocks that had been prepositioned for the Indo-Pacific. Those transfers have left other combatant commands operating with thinner margins than military planners consider ideal, particularly as the U.S. seeks to deter Chinese military action around Taiwan and reassure allies across the Pacific.

Asked for comment, chief Pentagon spokesman Sean Parnell told CBS News: "America's military is the most powerful in the world and has everything it needs to execute at the time and place of the President's choosing. We have executed multiple successful operations across combatant commands while ensuring the U.S. military possesses a deep arsenal of capabilities to protect our people and our interests." In 2022, Elbridge Colby, who was a defense official during the first Trump administration and is now the undersecretary for policy at the Pentagon, summed up the choices confronting an American military stretched across the globe: "A missile used in Europe can't be used in Asia," he wrote in Time magazine. He was commenting on the use of U.S. munitions in the war in Ukraine. But the latest stage of the American campaign against Iran has brought the same strategic dilemma into renewed focus. A year later, Colby argued that weapons that could be useful for defeating a Chinese attack along the first island chain — a string of islands off China's coast extending from Japan, through Taiwan and the Philippines — should be reserved for that purpose. The concerns of U.S. officials about current stockpiles involve some of those same weapons. During the ceasefire pause, a Center for Strategic and International Studies report said more than 1,000 Tomahawks and 1,100 JASSMs had been used and that replacement timelines were approaching four years. It said that supplies of air-defense interceptors are under even greater strain, as the U.S. burns through a significant share of prewar inventories of THAAD, SM-3 missiles and Patriots. These weapons face production timelines of up to five years. Taken together, the numbers suggest that the central problem is not simply cost but time. Many of the weapons being fired in weeks or months cannot be replaced for years.