A shortage in America is thus a shortage throughout much of the Western alliance, creating a cascading crisis of defence capacity. When viewed against the extraordinary expansion of missile arsenals among potential adversaries, this situation is alarming for the West.
When President Volodymyr Zelenskyy took part in the Coalition of the Willing summit in Kyiv last week, emphasising the need for more defensive missiles, he exposed an uncomfortable irony. Many countries who bought the expensive American Patriot systems find themselves without any ammunition to fire from them. Without doubt, Donald Trump’s war on Iran has served as a stunning advertisement for the effectiveness of Western missile defence, with Gulf allies reportedly intercepting more than 90% of incoming Iranian ballistic missiles. Yet this tactical triumph has illuminated a strategic vulnerability that poses a more profound threat to American security: the United States and its allies may simply not have enough missiles to fight the next war, or even to adequately deter it. Ballistic missiles screaming through the atmosphere at roughly a mile per second give defenders mere minutes to detect, track, and destroy them. Stopping one requires an extraordinary technological feat, effectively hitting a bullet with a bullet. For decades, the United States has led the world in developing that capability, with its Patriot and Terminal High Altitude Area Defence (THAAD) systems serving as the backbone of the missile shield protecting American forces and their allies across the world. In the conflicts in Ukraine and Iran, that shield has proved remarkably effective, with interceptors destroying hundreds of incoming missiles. But every successful interception consumes a single, irreplaceable asset. Replacing that interceptor is significantly harder and slower than firing one, and the wars have revealed that while the United States and its allies have built impressive missile defences, they have not built nearly enough of them.
According to estimates from the Centre for Strategic and International Studies, the United States has used approximately two-thirds of its pre-war Patriot interceptor stocks and roughly 40% of its THAAD stocks. Reports indicate that Patriot inventories have fallen from around 2,330 missiles to roughly 800, while THAAD stocks have declined from about 452 to around 250. The United States currently produces only about 650 Patriot interceptors annually, each costing roughly $4 million, while THAAD production has until recently been running at around 96 interceptors a year, each costing approximately $16 million. Even if every available production line were to operate at full capacity, it would take years to replenish the stocks already depleted during the conflicts. This is not merely a Pentagon accounting exercise, it is a fundamental problem of modern warfare that extends well beyond the Middle East. The United States is not the only country waiting for these missiles. Nineteen countries operate the Patriot system, including key allies like Germany, Poland, Japan, Ukraine, and Saudi Arabia, all of which are heavily dependent on American production and supply chains. A shortage in America is thus a shortage throughout much of the Western alliance, creating a cascading crisis of defence capacity.
When viewed against the extraordinary expansion of missile arsenals among potential adversaries, this situation is alarming for the West. China possesses thousands of ballistic missiles, and Russia has dramatically expanded its missile production to an estimated 120 ballistic missiles per month. It’s also well known that North Korea is actively supplying missiles to Russia, while Iran has demonstrated both the size of its arsenal and its willingness to use it. The fundamental arithmetic is becoming increasingly uncomfortable for America and its allies: missile production is accelerating, while missile-defence production is not. This problem is exacerbated by American doctrine, which often calls for two interceptors to be fired at a single incoming missile to increase the probability of a successful kill. This means an enemy firing one missile can force the defender to consume two extremely expensive weapons, creating an arms race where the attacker can potentially produce missiles faster and cheaper than the defender can produce interceptors to destroy them.
This problem did not begin with Iran; the war has merely exposed its severity. Russia’s invasion of Ukraine began drawing down Western stocks as the U.S. and its allies supplied Kyiv with weapons, and Israel’s subsequent conflicts placed further demands on missile defences. Military planners appear to have assumed they could simply stockpile for limited conflicts, but as the war in Ukraine has demonstrated, major modern wars cannot be fought from the stock-cupboard. The real question is not how many missiles America possesses today, but how quickly it can manufacture replacements tomorrow. This is a much more difficult question. Missile production depends on highly specialised components and supply chains that cannot be expanded overnight. It was recently announced that the American defence firm, Lockheed Martin, has been given a seven-year, $58.6 billion contract intended to triple production of the latest Patriot interceptor by the end of 2030, but production capacity measured in years cannot solve a shortage developing now.
Nowhere is this problem more acute than in Ukraine, whose ability to defend itself against Russian ballistic missiles has depended heavily on Patriot systems. In the first ten days of August alone, Russia reportedly launched almost 70 ballistic missiles at Ukraine, of which only one was intercepted, according to the Ukrainian air force. Zelensky has warned that Ukraine is running short of interceptors, a crisis compounded by the war in Iran. The U.S. has also used thousands of missiles that could have been reserved for its Pacific strategy or European defence, creating a strategic shortage that empowers adversaries in the region. Beijing has not fought a hot war since the 1979 conflict with Vietnam, and in the meantime has built a rapidly expanding arsenal of sophisticated ballistic, hypersonic and anti-ship missiles. The consequences for the Pacific theatre are therefore extremely worrying for the White House.
The United States has spent years warning China that an attack on Taiwan would be met with overwhelming American military power, yet much of that power depends on the same finite stocks of missiles and interceptors being consumed in the Middle East. Adding to concerns, more than 30 American ships have been redirected towards the Middle East, depleting the assets that would otherwise contribute to America’s Pacific posture. All the while, Taiwan and Japan are waiting for Patriot deliveries, which have reportedly been delayed. It has not gone unnoticed that this has created a classic Trumpian contradiction: the White House is urging its Asian allies to buy American weapons, yet the United States is struggling to deliver the weapons already ordered. Allies can hardly be blamed for questioning the reliability of American support when the weapons required to fulfil it are not available in a crisis.
The American president appears to have been completely oblivious to this obvious point, repeatedly insisting that US weapons stockpiles are not running low. This situation, of course, does not guarantee that China will invade Taiwan or that Russia will attack NATO. However, deterrence is not simply about what an adversary believes America is willing to do; it is about what America is physically capable of doing. If Beijing believes a prolonged conflict would rapidly exhaust America’s precision missiles and air defence interceptors, it may calculate that time is on its side. The age of assuming that sophisticated weapons will always be available when needed, is ending. The lesson of the Iran war is that success can create its own vulnerability. Every Iranian missile destroyed was a tactical victory, but every interceptor fired was also one fewer available for Ukraine, Japan, or American forces in the Pacific.
The West therefore faces a choice. It can continue treating missile defence as an expensive niche capability, producing enough weapons for limited conflicts and hoping wars remain short. Or it can recognise missile defence as a central component of national security and build the industrial capacity to sustain it: factories, skilled workers, secure supply chains, and enormous inventories. For decades, Western military planning has focused on technological superiority. The Iran war, however, has exposed a less glamorous but perhaps more important question: can that technology be manufactured fast enough? The current answer is simply ‘no’. In the next major conflict, the decisive advantage may not belong to whoever has the best missiles, but to whoever can make the most of them.
*John Dobson is a former British diplomat, who also worked in UK Prime Minister John Major’s office between 1995 and 1998. He is currently a visiting Fellow at the University of Plymouth.
