US Depletes Thousands of Missiles in Iran, Taiwan's Fate Now at Stake
The United States’ war against Iran is beginning to open up new issues for Washington. It is not just about the cost of war, but also about the depletion of important missile stockpiles that have long been the backbone of US military operations.
Based on an analysis from the Center for Strategic and International Studies (CSIS), in 39 days of US air and missile strikes during Operation “Epic Fury” before the ceasefire took effect, the US has used thousands of precision munitions. Some of these are expensive, limited weapons that require years to produce.
CSIS assesses that the US is not yet at the point of running out of ammunition for the Iran war. However, this large-scale usage is beginning to create risks for subsequent conflicts, especially if Washington must face a major war scenario in the Western Pacific.
Based on CSIS estimates, the US has already used more than 1,000 Tomahawk missiles from an estimated pre-war stock of 3,100 units.
The Tomahawk is a long-range missile that can be launched from the sea to strike land targets with precision.
In addition, the US has also used JASSM missiles for long-range air strikes. More than 1,100 units of this missile have been used from an initial stock of around 4,400 units.
Greater pressure is evident on air defence and missile systems. The US is estimated to have used 1,060 to 1,430 Patriot missiles from a pre-war stock of around 2,330 units. For THAAD, usage is estimated at 190 to 290 units from an initial stock of around 360 units.
The SM-3 missile, used to intercept ballistic missiles, is also estimated to have been used 130 to 250 units from a stock of around 410 units. Meanwhile, the SM-6 is estimated to have been used 190 to 370 units from an initial stock of around 1,160 units.
The problem is that these missiles cannot be produced and delivered quickly. CSIS notes that full delivery times for several key munitions can reach tens of months. The Patriot requires about 42 months, Tomahawk around 47 months, JASSM around 48 months, SM-6 around 53 months, THAAD around 53 months, and the SM-3 IIA could even reach 64 months.
In other words, additional defence budgets do not automatically make US missile stocks immediately available. It takes years for supplies to return to pre-war levels.
Depleted Missile Stocks Put Taiwan at Stake
This situation then drags in a larger issue, namely US readiness to face a conflict scenario in Taiwan.
Quoting a report from The Wall Street Journal, several US officials assess that the Iran war has depleted so much ammunition that Washington may not be able to fully execute contingency plans to defend Taiwan from a Chinese invasion if a conflict occurs in the near term.
According to the report, the US has fired more than 1,000 Tomahawk missiles since the Iran war began on 28 February 2026. In addition, the US is said to have used 1,500 to 2,000 important air defence missiles, including THAAD, Patriot, and Standard Missile.
Several US officials say that fully replacing those stocks could take up to six years. This situation has triggered internal government discussions on the need to adjust operational plans if at some point the president orders the US military to defend Taiwan.
Nevertheless, the report also emphasises that there are no signs of a conflict with China breaking out soon. US intelligence in March assessed that Beijing is unlikely to launch a war against Taiwan in 2027 and has no fixed schedule for unification.
The US government also denies that its military readiness is disrupted. The White House calls the report’s premise incorrect, while the Pentagon states that the US military has everything needed to carry out operations as per the president’s orders.
However, concerns about ammunition stocks cannot be ignored. China is not an opponent like Iran. Beijing has a far greater military strength, including ballistic missiles, drones, a large navy, and anti-access area denial capabilities that can limit the movement of US ships and aircraft around Taiwan.
In such a scenario, long-range missile stocks and air defence systems become extremely crucial. The more ammunition is used in the Middle East, the greater the pressure on US readiness in the Pacific.
CSIS also expresses similar concerns. The institution assesses that a war against a major power like China would consume ammunition at a higher rate than the Iran war.
Even before the Iran war, US stocks were assessed as insufficient to face a conflict with a peer competitor.
This means the Iran war has not left the US completely out of ammunition. However, this war highlights a major weakness in modern warfare. Missiles can run out far faster than the defence industry’s ability to produce them again.