The US has enough munitions for any plausible scenario in the Iran war, but replenishing depleted stockpiles will take "many years," according to a new report by the Center for Strategic and International Studies (CSIS).
Restoring pre-war reserves of four critical weapons that US forces used heavily during nearly 40 days of joint combat with Israel against Iran will take at least two years – and in some cases more than three years – the Washington-based think tank said Wednesday.
While US officials publicly voice confidence about weapons stockpiles, analysts suggest dwindling ammunition supplies may be shaping Washington's calculations on whether to resume war with Iran.
"Campaigns against Iran and its proxy forces – and for Patriot interceptors, aid to Ukraine – have made the problem more acute," the CSIS report stressed. "Alongside replenishing its own stockpiles, the US must also fulfill orders from allies and partners."
A CSIS finding last month showed four key weapons have been depleted by more than half of pre-war inventory: Tomahawk Land Attack Missiles (TLAM), THAAD interceptors, Patriot missiles, and ship-launched surface-to-air missiles SM-3 and SM-6.
JASSM air-to-ground missiles and PrSM precision strike missiles will take months to a year to replace, CSIS said. Pre-war PrSM stocks were low as the system is only starting production, while JASSM, though heavily used in the Iran war, will see large deliveries from recent orders.
"Decisions on how to allocate new production have created bilateral tensions, and these tensions will continue for several years as demand exceeds supply," the report warned.
The main issue is not funding but production time, limited manufacturing capacity, and lengthy procurement timelines, with CSIS noting past procurement levels were relatively low for many systems, slowing replacement efforts despite recent defense spending increases.
"There will be a vulnerability gap lasting several years until stockpiles return to previous levels and several more years before they reach levels desired by war planners," CSIS concluded.
US combat experience in recent conflicts may still help maintain deterrence against China during this replenishment period.
Evidence of depleted arsenals has emerged in recent weeks. The Washington Post revealed earlier this month that the US used more of its advanced interceptors to defend Israel than Israel itself did during 40 days of the Iran war.
The US Navy last week suspended a $14 billion weapons deal with Taiwan that Congress had approved but required President Donald Trump's signature. The Navy Secretary stated they need munitions for the Iran war.
Omar Ashour, professor of security and military studies at the Doha Institute for Graduate Studies in Qatar, previously told Al Jazeera that while the Iran war did not exhaust the entire US arsenal, it burned through some of the most critical and strategically valuable weapon classes. "This is not a tactical depletion but a strategic inventory shock, because that depletion will affect other theaters," Ashour said.
CSIS said last month that while the US has enough missiles to continue fighting in the Iran war, "the risk lies in future conflicts years down the line."
