WASHINGTON—Since February, the Iran war has reportedly depleted up to three-fifths of US Patriot interceptor stocks and as much as half of Terminal High Altitude Area Defense (THAAD) antiballistic missile stocks. Experts estimate that fully replenishing these stocks could take years.
The shrinking supply of air-defense missiles has reportedly become a factor in White House discussions about how quickly, and on what terms, the Trump administration should strike a deal with Tehran. At the same time, US officials have framed reports of depleted munitions from the Iran War as “misinformed.”
The US munitions situation affects far more than the conflict with Iran. Allies, partners, and adversaries around the world are watching for answers to several important questions: Will existing munitions be redeployed elsewhere? How is Washington preparing for the possibility of other crises occurring before inventories fully recover? Will the current munitions shortage shape longer-term perceptions about US deterrence and combat credibility?
The answers vary by region, and they would be exacerbated by additional, simultaneous conflicts. It’s therefore worth looking at where the munitions shortage is already altering calculations—and where its most consequential effects may still lie ahead.
The Middle East: An immediate test of endurance
In the Middle East, the impact is acute because the United States and its partners are expending interceptors while attacks continue.
Since February, Gulf states have absorbed thousands of Iranian drone and missile attacks, while relying heavily on US air and missile defense. Qatar, Bahrain, Kuwait, Saudi Arabia, and the United Arab Emirates all operate US-made defensive systems, including Patriot, Stinger, and THAAD missiles. Gulf states also rely on US-built offensive systems, such as High Mobility Artillery Rocket Systems (HIMARS) and Army Tactical Missile Systems (ATACMS).
As Iran sent wave after wave of missiles and drones earlier this year, the Gulf states turned to US-made interceptors to protect critical infrastructure and population centers. As a result, Saudi Arabia has reportedly reduced its PAC-3 MSE interceptor inventory by some 86 percent. And while there have been fewer Iranian attacks in recent weeks, the threat has nonetheless widened once again: A Houthi drone attack on Saudi Arabia’s Jazan Refinery this month shows that immediate demand for interceptors is likely to persist even if Washington and Tehran reach an agreement.
Iran’s approach has been both destructive and costly. It has learned how to stretch US and Gulf systems by pairing advanced missiles with cheap drones that are expensive to shoot down. As it draws out negotiations, Tehran is certainly aware that US munition stocks are now a factor in Washington’s ability to sustain the fight and defend its partners.
Israel is a unique case in the region but faces similar constraints. Its indigenous missile defense capabilities—including Arrow 3, Arrow 2, and David’s Sling—give it options that other US partners in the region do not have. However, US THAAD interceptors were used by the United States to defend Israel during the June 2025 strikes and this year during the early stages of the Iran war.
The Gulf countries are already assessing their next steps. Alliance diversification efforts, such as the Mecca Joint Defense Agreement signed last week by Saudi Arabia, Pakistan, and Turkey, show that Riyadh is seeking to demonstrate regional leadership and reduce its dependence on the United States. While the deal does not include arms transfers or munitions co-production, its efforts to advance regional cooperation, combined with a prolonged replenishment period for US munitions, could encourage Gulf states to pursue such agreements to meet defense shortfalls.
Europe: A race to rebuild first
Russia’s full-scale war on Ukraine, now in its fifth year, has unquestionably put pressure on European allies to hand over already insufficient munitions stocks. Germany has donated about one-third of its Patriot systems to Ukraine, while Poland reportedly transferred five PAC-3 interceptors to Kyiv. And Madrid and Athens face pressure from other European capitals to provide their older interceptor variants to Ukraine. Ukrainian President Volodymyr Zelenskyy underscored this week that his country remains desperate for PAC-3 and PAC-2 interceptors as Russia continues relentless ballistic missile attacks against Ukrainian civilians and critical infrastructure.
Although air-defense systems and interceptors have been central to both wars, Ukraine’s needs go beyond the systems most visibly depleted in the Middle East. Kyiv also needs artillery, long-range strike, armor, air, and naval capabilities. With a Pentagon-led European force posture review now underway, anxiety levels in Europe remain high even as US and European defense companies work to solve production and innovation issues to meet current and future needs.
NATO’s goal of spending 5 percent of gross domestic product on defense by 2035 is partly a munitions story, as it opens the question of whether increased spending will go to American or European defense companies. Germany, for example, has greatly increased munitions production capability in the past two years, albeit with a focus on medium-caliber ammunition. The European Commission has separately called for Europe to reach a sufficient defense posture by 2030, roughly matching assessments that Russia could be in a stronger position to use force against NATO within the next five years.
That the United States also finds itself overextended makes both the math and the politics harder for European capitals, many of which are prioritizing national defense needs. In April, the United States notified European allies of delays to some munitions deliveries due to the Iran war.
Russia is surely watching what is happening on both sides of the Atlantic closely. Moscow knows that it is also subject to the laws of physics when it comes to its own munitions depth, but it understands the politics of scarcity. If US intelligence assessments are right that Putin plans to “test NATO resolve” in the coming years, then the replenishment clock matters on both sides—and Russia is trying to recapitalize itself while fighting a full-scale war.
The Indo-Pacific: A medium-term problem, unless a Taiwan crisis comes first
US missile levels have also stoked renewed discussions about the implications for a possible conflict with China. Such a conflict would likely require a different weapons mix, especially maritime, stand-off, and long-range precision-guided missiles. But Patriot, THAAD, SM-3, and SM-6 would still be needed if Beijing were to launch an invasion or blockade of Taiwan.
Taipei is already feeling the pressure. In May, Acting Secretary of the US Navy Hung Cao stated that a planned $14 billion arms package for Taiwan had been paused in part to preserve munitions for the Iran war, although the US State Department later said that it was under review rather than paused.
The Trump administration’s stated priority for allies in the Indo-Pacific is self-reliance, and South Korea and Japan have responded differently to this charge. South Korea has become a major global arms supplier, ranking tenth in the world and focusing particularly on volume sales of rocket launchers, tanks, and missiles. South Korean defense companies sell to Poland, Estonia, Finland, Turkey, and Norway, among other US allies and partners.
Japan, meanwhile, lifted its longstanding ban on lethal arms exports in April, paving the way to expand its defense industry as tensions escalate with China and North Korea. At present, however, Japan is dependent on US foreign military sales as it builds stronger indigenous capabilities. Tokyo’s planned purchase of four hundred Tomahawk missiles, once set for delivery in 2028, was reportedly delayed because of US inventory concerns. For countries such as Japan, munitions sustainability has long been a planning issue before any regional conflict begins.
China does not need the United States to run out of weapons to exploit the strain. It continues to produce munitions and advanced weaponry, adding to already considerable stocks. As long as US replenishment and delivery timelines stay uncertain, Beijing is likely to prod for US vulnerabilities and sow doubt about Washington’s reliability as a security partner.
Africa and Latin America: A long-term credibility issue
Africa and Latin America mostly sit on the periphery of the munitions debate. But countries across both regions will watch how quickly the United States rebuilds its own stocks and how reliable it appears as a partner for military sales in the process. This will be relevant as China continues to offer alternatives in some weapons categories and security arrangements.
Egypt, Algeria, Morocco, Nigeria, and South Africa remain the biggest defense spenders in Africa, albeit with different security and purchasing priorities. But the United States should also focus on maintaining or expanding defense relationships in countries such as Angola, Mozambique, Ghana, Nigeria, and even Libya in order to address common security challenges and build economic opportunities given the continent’s growing geopolitical importance.
At the same time, Africa matters further upstream. Through several initiatives and executive orders, the Trump administration has sought to deepen US critical minerals partnerships. Neodymium, yttrium, and other rare earths are often used in magnets to produce weapons such as the PAC-3. The US bolstering its relationships with countries that export rare earths will not solve any munitions shortage today, but it could help build resilience over time.
In the Western Hemisphere, US defense deals have been smaller overall than in other regions, but they still matter for US credibility. Recent agreements, including Peru’s $3.42 billion F-16 deal and Argentina’s nearly $950 million package to arm its F-16s, are important signposts for US relations with Latin American partners as China continues to gain economic and political footholds across the region.
Even as it disputes reports of serious munitions shortfalls, the Trump administration has said that it wants to “supercharge” the defense industrial base. To achieve this, the United States will need to build a defense industrial base that can arm allies and partners through today’s wars while preparing for the next crisis. US strategic credibility will be shaped in part by whether allies, partners, and adversaries believe Washington can close that replenishment gap on a strategically relevant timeline.