How Rare Earths Power US Defence: Inside the F-35, Destroyers, and Submarines

A Virginia-class submarine leaves the shipyard carrying 4,600 kilograms of rare earth elements built into its hull and systems — more than eleven F-35 fighter jets combined. An Arleigh Burke-class destroyer carries 2,600 kilograms. The F-35 itself, the most advanced fighter in the US inventory, needs 418 kilograms per airframe. These are not trace quantities buried somewhere in a parts list; they are the physical material inside targeting pods, radar arrays, sonar transducers, and propulsion motors that make each platform work at all.

The arithmetic behind those numbers is uncomfortable for Washington. The United States is 80% reliant on China for its rare earth imports as of 2024, and China accounted for roughly 70% of all US rare earth imports across 2020-2023. More broadly, the US is 100% import-reliant for eleven separate mineral commodities that feed its defence-industrial base. A country that builds the world's most sophisticated weapons platforms is doing so on a supply chain it does not control — a fact that turns up in GS-3's science and technology and internal security themes, in GS-2 whenever the focus shifts to strategic dependence in great-power relations, and in Essay questions on self-reliance and the weaponisation of trade.

Three platforms, three very different appetites

The tonnage scales with the platform's complexity, not just its size:

• F-35 Lightning II fighter jet: 418 kg of rare earth elements per unit
• Arleigh Burke DDG-51 destroyer: 2,600 kg per unit
• Virginia-class attack submarine: 4,600 kg per unit

Each figure represents a different mix of function. The F-35 draws on rare earths for its advanced weapons targeting systems, radar technology, laser systems used for target determination, guided missiles, and the permanent magnets built into its flight-control surfaces and stealth-enabling systems. The Arleigh Burke destroyer — the backbone of the US surface fleet, with more than 70 hulls in service — spreads its 2,600 kilograms across advanced radar systems, missile guidance systems, and propulsion. The Virginia-class submarine carries almost double the destroyer's load across its Tomahawk missile systems, radar, drive motors, and sonar systems. A submarine hull, in other words, is not just steel and reactor fuel — it is a concentrated deposit of some of the hardest-to-refine materials on the periodic table.

What each element actually does

Two elements do the bulk of the structural work. Neodymium and praseodymium are the backbone of the high-strength permanent magnets used across all three platforms — in flight-control actuators, missile-guidance servos, and electric drive motors — because no substitute matches their combination of magnetic strength and weight. Strip those magnets out and an aircraft does not hold its stealth profile, and a missile does not steer as precisely.

Yttrium is the second load-bearing element, underwriting the radar performance and laser-targeting systems that appear on the F-35, the Arleigh Burke, and the Virginia-class alike — which is exactly why 93% of the yttrium compounds the US imports come from China. A further group — samarium, gadolinium, terbium, dysprosium, lutetium, and scandium — rounds out the list of elements the Pentagon treats as critical, feeding magnet performance at high operating temperatures, sensor calibration, and the specialised alloys used in stealth coatings and sonar components. This is not a defence-only supply chain, either: Lockheed Martin's production lines draw on the same Chinese-refined material as Tesla's battery plants and Apple's device manufacturing, which means a squeeze on the civilian side of the market tightens the defence side too.

An 80% dependence that can't be substituted overnight

The dependence is not really about mining — it is about refining. China produces roughly 90% of the world's refined rare earths and holds by far the largest global capacity for separation and purification, the chemically intensive step that turns raw ore into a usable metal or magnet. That processing chokehold is why the 80% import-dependence figure understates the real vulnerability: even rare earth ore mined outside China typically still needs Chinese facilities to become something a defence contractor can actually use. The same import-reliance problem extends into adjacent manufacturing inputs — the US is 100% import-reliant for graphite, used in lithium-ion battery anodes, for manganese, used in steel and battery alloys, and for fluorspar, essential to aluminium production — all of which sit in the same defence-industrial supply chain as the rare earths themselves.

Mountain Pass: one mine, and ore that still goes to China

The United States has exactly one active rare earth mine — Mountain Pass, in California's Mojave Desert — and it sits on one of the richest rare earth deposits anywhere in the world. On paper, that should anchor a self-sufficient supply chain. In practice, it does not: despite the scale of the deposit, ore from Mountain Pass is still shipped to China for the final separation and processing that turns it into usable metal, because the US has not rebuilt the mid-stream refining capacity that China spent three decades building out. Owning the rock is not the same as owning the supply chain.

The vulnerability inside a Virginia-class submarine is not that America lacks rare earth deposits — Mountain Pass proves otherwise — but that it lacks the mid-stream refining capacity to turn what it digs up into a finished magnet without sending the ore to the same rival it is trying to out-build.

The alternatives on paper don't close the gap

Washington's diversification effort shows up in trade data, but the numbers stay small next to China's share. Malaysia supplies 13% of US rare earth imports, Japan 6%, Estonia 5%, and every other source combined accounts for just 6% more. Together, these alternative suppliers still leave the bulk of US demand resting on a single country, which is precisely the leverage China has tested directly: Beijing imposed export restrictions on rare earth magnets and later expanded those restrictions to seven elements — samarium, gadolinium, terbium, dysprosium, lutetium, scandium, and yttrium — in response to US tariff escalation, a squeeze that left automakers including BMW, Mercedes-Benz, and Ford flagging production disruptions within months. For a defence-industrial base running on the same elements as an F-35's targeting pod, that kind of disruption is not a commercial inconvenience; it is a readiness problem.

Ukraine's reserves and Washington's strategic calculus

This is the gap that has pulled Ukraine's mineral wealth into US strategic planning well beyond the battlefield. Ukraine holds Europe's largest recoverable rare earth reserves, a fact frequently cited as an additional factor behind Russia's invasion, since control over those deposits would deny the West an alternative source sitting outside Chinese control. The Trump administration has since worked to secure US access to Ukrainian mineral resources as part of a broader effort to diversify away from Beijing — placing a European war and a Pentagon supply chain problem on the same strategic map. None of this changes the underlying platform math: the 418 kilograms in an F-35, the 2,600 in a destroyer, and the 4,600 in a submarine still have to come from somewhere, and for now, most of it still starts in China.

For UPSC aspirants, the value of this case lies less in memorising kilogram figures and more in tracing the chain from platform to material to function to import source to vulnerability — that structure is what turns a data point into an analytical answer. Building the discipline to move fluently between the strategic and the technical, between why yttrium matters on a warship and why Mountain Pass alone cannot fix the problem, is exactly the kind of preparation our GS Foundation (GS-3 Security) programme (/courses/gs-foundation/) is built around.