Leaks from the Pentagon last week – as reported by US media – have suggested that if attacks on Iran continue for more than 10 days, US stocks of some critical missiles could begin to run out.
On Saturday, the United States and Israel launched strikes against Iran as talks continued between Washington and Tehran over Iran’s nuclear program and other issues, understood to include limiting Iran’s possession of ballistic missiles and ending arms supplies to regional armed groups.
Iran responded with missile and drone attacks across the region, including targets in Israel and US military assets in Bahrain, Saudi Arabia, Qatar, the United Arab Emirates and Iraq.
The Pentagon, headquarters of the US Department of Defense, is also believed to have warned President Donald Trump that a prolonged military campaign in Iran would carry serious risks, including the high cost of replenishing Washington’s dwindling ammunition stockpile.
Trump has maintained that the United States has enough reserves to keep the military campaign in Iran going.
“America’s ammunition stockpile, in the mid and upper mid grade, has never been higher or better. As I was told today, we have a virtually unlimited supply of these weapons. Wars can be fought ‘forever’ and very successfully, using only these supplies,” Trump wrote in a Truth Social post on Tuesday.
While Trump said on Monday that the plan for war against Iran was initially “projected within four to five weeks” but could continue for longer, analysts told Al Jazeera that some weapons in his arsenal may have been depleted by then, particularly crucial interceptor missiles.
This is what we know.
What weapons does the United States use in its attacks against Iran?
According to the US military’s Central Command (CENTCOM), it has deployed more than 20 weapons systems in air, sea, land and missile defense forces during its ongoing operation in Iran.
The United States is using B-1 bombers, B-2 stealth bombers, F-35 Lightning II stealth fighters, F-22 Raptor aircraft, F-15 and EA-18G Growlers.
It also uses long-range strike drones and systems, including low-cost unmanned combat strike system (LUCAS) unidirectional drones, MQ-9 Reaper drones, M-142 High Mobility Artillery Rocket Systems (HIMARS), and Tomahawk cruise missiles.
In addition, it is using air defense systems such as the Patriot, Terminal High Altitude Area Defense (THAAD) batteries and Airborne Warning and Control System (AWACS) aircraft.
Two American aircraft carriers, the USS Abraham Lincoln and the USS Gerald R Ford, were in the Middle East when the attack on Iran began.
The Wall Street Journal reported on Feb. 23 that Pentagon officials and Gen. Dan Caine, chairman of the Joint Chiefs of Staff, had warned Trump about the dangers of a prolonged campaign against Iran.
At the same time, The Washington Post reported that Caine had told Trump that a lack of critical ammunition and support from regional allies could hamper efforts to contain a possible Iranian retaliation in the event of a US attack.
According to the report, US ammunition stockpiles, including those used in missile defense systems, have been depleted by their use in support of allies such as Israel and Ukraine.
Trump lashed out at media reports that Caine had issued such a warning, adding that the general “believed” in a war with Iran.
How much weapons did the United States use in attacks against Iran last year?
Iran fought a 12-day war with Israel from June 13 to 24, 2025. The United States joined the campaign on Israel’s side, bombing several Iranian nuclear facilities toward the end. During this time, the United States deployed two of its advanced THAAD missile defense system batteries to Israel.
THAAD is an advanced missile defense system manufactured by Lockheed Martin that uses radar and interceptor missiles to shoot down short-, medium-, and intermediate-range ballistic missiles at ranges of approximately 150 to 200 kilometers (93 to 124 miles).
After the 12-day war, U.S. officials reported that they had to fire more than 150 of these missiles to intercept incoming Iranian missiles, multiple news reports said, representing about 25 percent of their THAAD interceptors.
According to US media reports, the United States also ran out of a large number of shipboard interceptors during last year’s war.
What weapons could the United States run out of now?
If the war with Iran continues, the United States will most likely have shortages of high-end, precision munitions and interceptors like THAAD, analysts say.
This includes Joint Direct Attack Munitions (JDAM), which are guidance tools that use the Global Positioning System (GPS) to convert unguided bombs into precision-guided munitions, effectively turning “dumb” bombs into “smart.”
A THAAD battery is typically composed of 95 soldiers, six truck-mounted launchers, 48 interceptors (eight for each launcher), a radar system, and a fire control and communications component. According to Lockheed Martin, there are nine active THAAD batteries around the world by mid-2025.
In 2024, Al Jazeera’s Mike Hanna reported from Washington, DC, that a THAAD battery costs between $1 billion and $1.8 billion.
It takes months to assemble, integrate and test interceptors and munitions. Additional time is then needed to transport them by sea and air, configure them and deploy them.
Experts say high-end missile defense systems are primarily designed to deal with limited, high-intensity attacks from states such as Russia, China or North Korea, rather than large, sustained barrages of cheaper missiles.
Over time, finite stocks of advanced interceptors will be depleted at great cost, analysts say, as each intercept can cost hundreds of thousands or even millions of dollars to shoot down a missile that may have only cost a few thousand dollars to build.
Speaking to reporters on Monday, US Secretary of State Marco Rubio said Iran is capable of producing many more offensive weapons than the US and its allies can build interceptors to stop them.
“By some estimates, they are producing more than 100 of these missiles a month. Compare that to the six or seven interceptors that can be built a month,” Rubio said.
“They can build 100 of these a month, not to mention the thousands of one-way attack drones they also have. They’ve been doing this for a long time. And by the way, they’ve been doing it under sanctions.”
Additionally, stocks of the Standard Missile 3 (SM-3) are already running low due to slow production, attacks on Yemen’s Houthi rebel group, and past clashes with Iran. The SM-3 is a warship-launched anti-ballistic missile interceptor.
The United States is not only running out of weapons, it is also losing them due to miscalculations in the campaign. For example, on Sunday, at least three U.S. planes were shot down over Kuwait in what U.S. officials described as a friendly fire incident.
How soon could the United States run out of interceptors?
Christopher Preble, a fellow at the US think tank Stimson Center, told Al Jazeera that while the US can afford the financial cost of war given its trillion-dollar defense budget, the real limitation is the stockpile of interceptor missiles such as the Patriot and SM-6.
Preble warned that high interception rates cannot continue indefinitely.
“It is reasonable to speculate that the pace of operations at this time, in terms of number of interceptions, could not continue indefinitely, certainly, and perhaps could not continue for more than several weeks,” he said.
Manufacturing replacements are not instantaneous. “A Patriot missile or an SM-6… is a very complicated piece of equipment,” he added.
Preble said he could not comment on how long it takes to make the weapons.
“It’s not like they’re producing them, hundreds or thousands a day. That’s not the pace of manufacturing.”
What happens if the United States runs out of some weapons?
Preble said the United States could continue making weapons or move them to the Middle East from other deployments.
“Some of these interceptors are used or were intended to be sent to Ukraine to counter Russian attacks against Ukraine,” he said.
“Some of them are used in Asia, in the Indo-Pacific, and they are not currently used, but they would be important in the event of a contingency in the Indo-Pacific. So there would be some concern about removing those weapons from that theater.”
How much is this war costing the United States?
While the Pentagon has not revealed how much the war is costing the United States, estimates suggest that sustaining it will be extremely costly.
Reports from the Anadolu news agency suggest that the United States spent around $779 million in the first 24 hours of its operation in Iran, with another $630 million for pre-strike preparation: moving aircraft, deploying more than a dozen warships and mobilizing regional assets.
The Center for a New American Security estimates that it costs about $6.5 million per day to operate an aircraft carrier strike group like the USS Gerald R. Ford.
