What Happens If the U.S. Can’t Get Enough Magnesium? You Don’t Want to Find Out.

Magnesium ingots, which produces magnesium alloy, is critical to national defense-related manufacturing. (Christinne Muschi/Bloomberg)

About the authors: Lt. Col. Jahara Matisek, PhD, is a U.S. Air Force command pilot, nonresident research fellow at the U.S. Naval War College and the Payne Institute for Public Policy, and a visiting scholar at Northwestern University. Morgan D. Bazilian is the director of the Payne Institute for Public Policy and professor at the Colorado School of Mines. He was formerly lead energy specialist at the World Bank. Alex Grant is CEO of Magretha.

The U.S. will finally start refining magnesium again. Earlier this month, two companies announced a joint venture in Arkansas. It would be the first credible attempt in years to restore domestic control over a material the Pentagon must have to fight a modern war.

Magnesium is the lightest structural metal on earth, yet it carries one of the heaviest burdens for U.S. national security. It is a vital input to the defense industrial supply chain. Aircraft-grade aluminum alloys, missile and aerospace castings, countermeasure flares, nuclear-reactor materials, even the production metallurgy for zirconium, hafnium, boron, and beryllium all require magnesium. But China controls 95% of global magnesium production, upon which the U.S. relies.

The last American magnesium producer, U.S. Magnesium, shuttered operations in 2021. The company’s subsequent bankruptcy in September left the Pentagon staring at a single-point-of-failure scenario.

This vulnerability exposes a deeper reality: Magnesium is far more than a critical mineral. Rather, it is a material whose absence cascades across entire industrial ecosystems. Europe learned this the hard way in 2021, when an abrupt squeeze in Chinese magnesium exports nearly shut down its automotive and aluminum industries.

If Chinese supply to the U.S. were similarly squeezed again, the U.S. would likely face a similar meltdown in a matter of weeks. We have even heard from people at the Pentagon that if China cuts off magnesium supply to the U.S., it will have six months to decide to go to war. After that, we wouldn’t be able to wage war at all.

That is because the supply of one kilogram of magnesium affects the production of hundreds of tons of downstream industrial materials. Nearly every aluminum alloy used in airframes, ground vehicles, naval structures, and space systems depends on a small percentage of magnesium that improves strength, ductility, and corrosion resistance.

Remove magnesium and you lose the capabilities of the modern defense industrial base: aluminum rolling and extrusion, steel production, automotive manufacturing, and aerospace manufacturing. Losing magnesium would mean a dismantling of American warfighting capabilities.

Making matters worse, China has demonstrated its willingness to weaponize this supply chain against the U.S. several times in the past 20 years. During the latest disruption in 2022, Kaiser Aluminum had to slash output by 50%. Major automakers almost halted automotive production lines because magnesium-containing alloys had run low.

The U.S. consumes roughly 100,000 tons of magnesium a year—small enough to stabilize with strategic intervention, yet large enough that stockpiling alone is insufficient. The only credible path is restoring consistent, reliable domestic production through a careful strategy.

First, there urgently needs to be a primary domestic producer of magnesium. Promising projects, including the government-backed effort with Magrathea, is demonstrating new technologies capable of producing U.S.-sourced magnesium at globally competitive cost.

Second, Washington needs targeted industrial-financing tools to get processing plants built. These solutions already exist, such as conditional loan guarantees, multiyear offtakes, and price floors. Steps toward rebuilding America’s rare-earth magnet base have already begun, with the Trump administration’s help. Magnesium demands a similar playbook and similar prioritization. A conditional federal loan guarantee paired with a modest equity investment would catalyze full-scale U.S. production by 2028.

Third, embed concentration-trigger thresholds directly into the Pentagon’s acquisition programs for weapon systems. Under such a model, when U.S. magnesium import reliance exceeds a set proportion—say, 50% from any one country—automatic stabilization measures activate. Those could include offtakes, tariff-rate quota adjustments, or price floors. Likewise, if any single foreign producer accounts for more than 35% of the supply entering the U.S., the Pentagon could trigger protective actions. These thresholds convert magnesium from a passive risk into an actively managed strategic material, preventing crisis-driven scrambles. Finally, magnesium planning must be linked to levels needed to surge readiness for aerospace alloys and other economic and military use purposes.

The U.S. once faced similar crossroads as World War II began. Washington invested in the Dow Chemical magnesium refinery on the Gulf Coast—the largest ever built—and used seawater as its feedstock. That move enabled the U.S. to outproduce Axis powers in aircraft three to one. The logic that guided Washington throughout World War II applies today. The country controlling its magnesium controls the industrial means of war.

For about the cost of two F-35s, roughly $200 million, the U.S. could end its reliance on external suppliers for defense applications. That is a price worth paying.

Guest commentaries like this one are written by authors outside the Barron’s newsroom. They reflect the perspective and opinions of the authors. Submit feedback and commentary pitches to ideas@barrons.com.