The United States Has Run Short of Missiles. That Changes the Iran War

IT IS A PATTERN by now. Mr Trump threatens to hit Iran "very hard". A day or two later, he says the attack is cancelled, usually because a deal is imminent or a regional ally has asked him to pause. The cycle began in February, when the United States and Israel launched attacks on Iran, and has repeated itself at least seven times since. On August 1st, the latest iteration, Mr Trump wrote on his Truth Social platform that he had agreed to cancel the attack "subject to being able to rapidly make a DEAL". Iran's defence minister was unsurprised, saying that the armed forces remained on high alert.

The surface explanation for Mr Trump's vacillation is personality. The president is impulsive, enjoys the theatre of brinkmanship, and prefers the photo-op of a de-escalation to the messy aftermath of an invasion. There is truth in that. But personality is not the structural constraint. The constraint is ammunition.

The United States, it turns out, is running low on missiles.

According to the Center for Strategic and International Studies, a Washington think tank, the United States has expended roughly two-thirds of its pre-war Patriot interceptor inventory in five months of conflict, leaving fewer than 1,000 where there were about 2,300. THAAD interceptors, another key layer of ballistic-missile defence, have fallen by about 38%, to between 234 and 278. The CSIS analysts, Mark Cancian and Chris Park, are blunt: there are no good alternatives to Patriot and THAAD for defending against ballistic missiles. The munitions shortage has, in their words, "entered the national debate and reportedly become a major element in presidential decisionmaking".

That matters for the Iran war, but the wider implication is more alarming. The depleted stockpiles leave a near- to medium-term window of vulnerability should another high-intensity conflict erupt, particularly in the western Pacific against China. Even before the Iran war, the Pentagon's munitions were deemed insufficient for a peer-competitor fight. Now the shortfall is acute. Rebuilding will take years. As Mr Cancian told the BBC, money committed today would not produce a missile for three to five years. The Army has awarded Lockheed Martin a contract worth up to $58.6bn to produce more Patriot interceptors through 2032. That is a response, but it arrives late.

The trouble is not merely that the United States has fewer missiles. It is that Iran has found a way to inflict disproportionate damage with relatively few.

Iran's strategy has been simple and effective. Rather than matching the United States strike for strike - which it could not hope to do, given the disparity in military power - it has choked the Strait of Hormuz, the narrow waterway through which about 20% of global oil supply flows. The closure, which began in March, has produced what the International Energy Agency has called the largest supply disruption in the history of the global oil market. Brent crude has surged past $120 a barrel. QatarEnergy declared force majeure on all its liquefied natural gas exports. European gas storage, already at historically low levels, faced a second energy crisis.

Iran has also struck desalination and power facilities in Kuwait, Saudi Arabia, and Jordan, forcing Gulf states to absorb damage while mediating between Tehran and Washington. The result is a stalemate in which neither side can claim victory and both are bleeding. The United States and Israel have done well in conventional military terms - Iran's missile attacks fell by 90% in the first week, and over 250 Iranian leaders, including the supreme leader, have been killed. But Iran's regime survives, the strait remains closed, and American munitions dwindle.

To be sure, the United States can continue fighting. CSIS concluded earlier this year that enough munitions remain for any plausible scenario in the Iran conflict. The danger is not running out tomorrow. It is the compound effect of daily interceptor expenditures, the impossibility of replacing them quickly, and the growing likelihood that the war drags on without a decisive endpoint. Each day the strait stays closed, Iran's economic pain accumulates alongside America's. But Iran is a smaller economy, more used to sanctions, and its leaders have a vested interest in regime survival that outweighs most other considerations. The United States, by contrast, faces domestic political pressure from voters paying $4.31 a gallon for petrol, allied irritation from a war begun without consultation, and a defence budget that must cover Ukraine, the western Pacific, and the Middle East simultaneously.

This is where the CSIS analysis of munitions depletion becomes a story about strategic weakness. The post-Cold War defence posture assumed limited regional conflicts against weaker adversaries like Iraq and North Korea. The industrial base was deliberately shrunk after 1993 - then-Deputy Secretary of Defence William Perry told defence contractors to "merge or diversify", reducing the number of prime aerospace and defence contractors from 51 to five. Production was optimised for peacetime efficiency, not wartime surge. Munitions competed poorly in the Pentagon's budget process, losing out to more visible platforms such as aircraft and ships. The United States went to war with an industrial base that was never designed for the kind of munitions-intensive conflict it is now fighting.

The pattern of Mr Trump's announcements becomes more legible against this backdrop. When the United States is short of interceptors, the cost of escalation is higher. When a ceasefire offers a chance to conserve dwindling stocks, the incentive to pause is not merely political - it is logistical. That does not mean Iran has "won". It means that the arithmetic of attrition favours the side that can absorb the cost of waiting. Iran, having spent decades preparing for isolation, is better positioned for that test than the United States is for running out of missiles before a political settlement.

The stronger counter-argument is that military superiority cannot be reduced to a count of interceptors. The United States has deep stockpiles of cheaper munitions, such as JDAM-guided bombs, and retains overwhelming air power. It can still strike Iranian targets at will. A settlement will come when the United States decides the economic cost of the Hormuz closure outweighs whatever military objective remains. That is a valid point. But it conflates tactical capability with strategic patience. The question is not whether the United States can destroy Iran's military - it has done most of that already. The question is whether it can sustain the political and industrial will to finish the job.

A wiser approach would have been to anticipate the munitions problem before launching a war. Failing that, the United States should now pursue a settlement on terms that secure the reopening of the strait even if they fall short of regime change or total nuclear surrender. The aim should be to end the daily burn of interceptors, stabilise energy markets, and begin the multi-year process of rebuilding stocks for the conflict with China that actually threatens American primacy. Continuing to cycle between threats and pauses is not strength. It is a recognition that the costs of escalation are rising faster than the benefits.

Iran may well see weakness in the American pattern. But the real lesson is not about Tehran's confidence. It is about Washington's failure to align its industrial capacity with its strategic ambitions. You cannot fight two wars - one in the Middle East and one against China - with the munitions budget of a peace that ended more than three decades ago. That bargain is breaking.