Analysts say the pause exposes a vulnerability long ignored, where national security depends on supply chains outside U.S. control. A 2023 Government Accountability Office report warned that the Department of Defense had not conducted a comprehensive rare earth supply chain risk assessment in over a decade. That report was shelved. Those warnings are now being revisited.

Contractors are scrambling. Prices for neodymium surged 18% in twenty-four hours — the largest one-day increase since 2011. Dysprosium prices rose 22%. Praseodymium, used in high-strength magnets for guidance systems, jumped 15%. Defense contractors are now competing with commercial buyers for dwindling stockpiles, driving prices even higher.

Planners are revisiting assumptions they once treated as settled fact. For decades, the U.S. defense establishment assumed that allied nations — Canada, Australia, the United Kingdom — would never restrict critical mineral exports. That assumption, like so many others in an era of trade wars and geopolitical competition, is now in question.

The specific systems at risk are numerous. The F-35’s electro-optical targeting system requires rare earth magnets. The Navy’s AEGIS radar system depends on rare earth components. The Army’s Apache helicopter uses rare earth elements in its targeting and navigation systems. Without Canadian supply, every one of these systems faces potential production delays.

The human consequences are already visible. At a Lockheed Martin facility in Texas, workers were told to expect “reduced shifts” if the pause continues. At a Raytheon plant in Massachusetts, procurement officers have been reassigned from development projects to supply chain hunting. “We are calling every rare earth broker in the world,” one manager said. “No one has excess inventory.”

If the pause stretches on, this moment could force a hard rethink of defense readiness itself. The Pentagon has long relied on private industry to manage supply chain risks. But private industry cannot stockpile years’ worth of rare earth elements. Only governments can do that — and the U.S. government has not made the investment.

As the sun set over the Pentagon, officials gathered for an emergency meeting on rare earth strategy. Options on the table include releasing material from the National Defense Stockpile, accelerating domestic mining permits, and diplomatic outreach to Ottawa. But none of these options produce results in days. They take months or years. And the pause is already in effect.

Canada, for its part, has given no indication of when the “temporary review” might end. Trade experts speculate that Ottawa is using rare earth leverage to extract concessions on other disputes — dairy, lumber, auto tariffs. But for defense contractors watching their production lines slow, the reason matters less than the result. The minerals are not crossing the border. And until they do, America’s weapons systems are building up a backlog that no amount of political spin can fix.