How long can the US sustain the Iran war? Pentagon warns of looming missile shortage

Amid an escalated conflict in the Middle East, the United States, which entered a “war of its choice” is facing concerns over its declining array of weapons supplies as the tensions show no sign of stopping on its fifth day. This comes amid US President Donald Trump's indications that the war in Iran could last for four to five weeks or even longer.

According to reports by the Wall Street Journal, CNN and News18, stocks of critical missiles could run low if the war lasts for another 10 days.

The official warned of a “major uptick” in strikes over the next 24 hours while acknowledging that the artillery may run low.

In the initial phase of strikes, Iranian defences were weakened, according to a report by News18. The next phase aims to destroy Iran's missile manufacturing facilities unmanned aerial vehicles and naval capabilities.

However, all this comes on the backdrop of a Pentagon crisis.

The US War Department is reportedly also facing shortages of Patriot missiles, owing to the fact that Ukraine had already used a large stock of it during its four-year-long conflict with Russia.

As per a Wall Street Journal report, the repeated conflicts with Iran and its allies in the Middle East are eating into US' weapons storage.

The precise stock of US air-defense interceptors—what the Pentagon calls magazine depth—is classified. And there are more US strikes on Iran to come.

“One of the challenges is you can deplete these really quickly,” Kelly Grieco, a senior fellow at the Stimson Center think tank who used to teach at the Air Command and Staff College, told WSJ. “We’re using them faster than we can replace them.”

Concerns regarding the Thaad antimissile system that was deployed to Israel in 2024 is also beginning to show. Amid the attacks from Iran, the Pentagon's concern is to maintain a sufficient stock of interceptors for the Thaad.

Stocks of Patriot and Standard Missile interceptors also need to be replenished soon. These are used to take out aerial threats and are being used to defend against Iranian missiles and drones.

Patriots can intercept lower-flying threats, while SM3s can take down ballistic missiles above the atmosphere of the earth.

The US is also experiencing a shortage in sea-launched Tomahawk cruise missiles, widely known as TLAMs, and aircraft-launched weapons against Iranian targets.

However, according to the WSJ report, Israel is facing concerns on arms supply as well. The stock of its Arrow 3 air-defense interceptors, as per the report quoting another US official.

The cost of the war is also a concern. According to the News18 report, the first 24 hours of strike alone costed $779 million.