In October 2025, China announced rare earth export controls that reached past its own borders, including a license requirement for some foreign-made products that contain Chinese rare earths. A month later, after a trade truce, its Commerce Ministry suspended them through November 10, 2026 (BNN Bloomberg, November 7, 2025; Clark Hill, November 24, 2025).

In late September, the ministry said the wider trade arrangement with the United States would run to January 10, 2027, but its statement did not name rare earths (Rawmaterials.net, September 28, 2026). And one set of controls never paused. China's licensing on seven medium and heavy rare earths, including dysprosium and terbium, still applies (Clark Hill, November 24, 2025).

Whichever way Beijing goes, the risk for a defense program is one the F-35 program has already lived through.

In September 2022, the Pentagon stopped accepting new F-35 fighters. The problem wasn't the engine, the radar or the stealth coating. It was a magnet.

The magnet sat inside a pump in a Honeywell unit on the jet. Its alloy came from China, which may have put it out of line with defense purchasing rules. Nobody at the top of the program found it. Honeywell's pump supplier told Honeywell that one of its own suppliers had used the alloy, and Honeywell told Lockheed Martin. The F-35 Joint Program Office said there were no performance, quality, safety or security risks, and still paused deliveries (Defense News, September 7, 2022).

Eighteen jets waited about a month. Deliveries resumed on October 8, 2022, only after the Pentagon's top acquisition official signed a national security waiver and Honeywell found a different source for the material (Air & Space Forces Magazine, October 11, 2022).

The prime contractor never bought that magnet. It never signed a contract with the company that made it. And that company held up a fighter program. That is the hidden single point of failure: the one small supplier, deep in the chain, that nobody above it can see until it stops.

Why one small shop can stop a big program

Defense supply chains have narrowed for decades. In its February 2022 competition report, the Department of Defense, now the Department of War, found that aerospace and defense prime contractors shrank from 51 to 5. Tactical missile suppliers fell from 13 to 3, and only two domestic suppliers of solid rocket motors remained. The report warned that "having only a single source or a small number of sources for a defense need can pose mission risk" (Office of the Under Secretary of Defense for Acquisition and Sustainment, February 2022).

The same month, the department's supply chain report said it "has limited visibility into some sub-tiers of defense supply chains." It named sole-source dependencies for the chemicals used to make explosives and propellants, and said the United States "has only one foundry that can produce the large titanium castings required for some key systems" (Department of Defense, "Securing Defense-Critical Supply Chains," February 24, 2022).

When there are only a few sources at every level, losing one small job shop leaves no backup. The big names get the attention. The small shop with the one qualified heat-treat line or the one certified casting gets none, until it fails.

Three programs, one pattern

Rocket motors. In October 2023, L3Harris Chief Executive Christopher Kubasik said of the company's rocket motor business, "We only have, in some cases, one or two certified suppliers of cases and igniters and sometimes nozzles" (Defense One, October 27, 2023). That business supplies motors for Javelin, Stinger and the Guided Multiple Launch Rocket System. Nine months later, at the Farnborough Airshow, Lockheed Martin's Tim Cahill said, "We are still struggling to get everything we need as a builder" (Breaking Defense, July 23, 2024). Limits a few tiers down at one motor maker held back two of the largest missile makers in the country.

Submarines. In September 2023, Representative Joe Courtney called castings "the real sort of kink in the garden hose." The Navy had mapped 16,000 suppliers in the submarine industrial base and found 15 critical chokepoints (Defense News, September 8, 2023). A year later, General Dynamics Chief Executive Phebe Novakovic said its submarine yard was "severely impacted by late deliveries from major component suppliers" and would slow construction to match, because work done out of sequence can cost up to eight times as much (The Maritime Executive, October 24, 2024). A late part doesn't just delay the work. It makes the rest of the work more expensive.

Artillery shells. In July 2026, the Department of War Inspector General reported that, according to Army program officials, "projectile metal part production is the limiting factor" in reaching 100,000 155-millimeter shells a month. As of March 2026, output was 36,000 a month. A new plant in Mesquite, Texas, had not produced a single shell body that met the contract's minimum requirements, and with only three facilities making those parts, output tops out at 71,000 a month (Department of War Inspector General, DOWIG-2026-095, July 9, 2026). One step in the chain sets the ceiling for the whole program.

Why it stays hidden

Two reasons, and the government has named both.

First, nobody can see that far down. The Government Accountability Office found that the department estimates more than 200,000 suppliers help produce its weapons and goods, and that its efforts "provide little insight into the vast majority of suppliers, including those that provide raw materials and parts" (Government Accountability Office, GAO-25-107283, July 24, 2025). The single points of failure live in exactly those tiers.

Second, the small shops are fragile. The National Defense Industrial Strategy lists "sub-tier supplier fragility" as a challenge, noting that these suppliers "can sometimes operate on narrow profit margins," which leaves them exposed to swings in demand and budgets (Department of Defense, National Defense Industrial Strategy, released January 11, 2024). A shop that loses money on defense work one year may not be there the next.

How to find your single points of failure

This isn't only a defense problem. Any manufacturer with long, specialized supply chains has the same risk. After more than 20 years in supply chain and procurement, the lesson I keep coming back to is simple: the supplier that stops you is usually one you never bought from directly. Here is how to find yours.

  • Map below tier one for your critical items. Start with the 20 items that would stop your line or your program. Ask each tier-one supplier who makes the parts and materials inside their parts.
  • Look hardest at special processes and materials. Castings, forgings, heat treatment, plating, magnets, energetics and microelectronics are where single sources hide.
  • Count qualified sources, not names on a list. A second source that hasn't passed your qualification isn't a source. It's a plan.
  • Trace country of origin back to the material. Defense rules are moving that way. From January 1, 2027, the restriction on magnets, tantalum and tungsten from China, Russia, North Korea and Iran reaches back to where the material was mined (Defense Federal Acquisition Regulation Supplement 252.225-7052).
  • Know which critical items ride on Chinese rare earths. Magnets are the obvious ones, but check motors, actuators and sensors too. If China's licensing comes back, those are the items to watch first.
  • Price the stop, not the part. The question isn't what the part costs. It's what it costs when the part doesn't arrive.
  • Fund the second source before you need it. The government has started doing this itself. In July 2025, the department took a $400 million stake in MP Materials and agreed to buy all of the planned magnet plant's output for 10 years (MP Materials filing with the Securities and Exchange Commission, July 10, 2025). A second source is cheaper to build before the stop than after it.

What to do this week

If you take one thing from this, make it this: pick your five most critical items and ask, for each one, "If one supplier below tier one disappeared tomorrow, would you know, and would you have a backup?"

If the answer is no for any of them, that's your single point of failure. You found it before it found you.