Defense leg — primes + defense-tech × the rare-earth chokepoint
Built from research/defense-rare-earth.json (web-verified: CSIS, Modern War Institute/West Point, GAO/CRS-cited reporting, DoD FY26 budget, Arnold/Dura Magnetics). Per-unit REE figures are widely-cited GAO/CRS-lineage estimates — treat as order-of-magnitude. Models: models/graph/defense_web.py, models/z3/defense_chokepoint.py.
Thesis. US weapons systems are materially dependent on rare-earth magnets China controls — and China has moved from owning the supply to explicitly denying it to foreign militaries. This is the hard, near-term national-security chokepoint behind the defense-contractor leg.
1. The per-system dependency (order-of-magnitude)
| System | REE kg/unit | Samarium kg | Note |
|---|---|---|---|
| F-35 | ~418 (~900 lb) | 22.6 | SmCo magnets for high-temp (missile nose cones); Lockheed = largest US samarium user. Block-4 upgrade slipped 2026→2031, +$6B. |
| Virginia-class sub | ~4,200 (~9,200 lb) | 50 | |
| Arleigh Burke destroyer | ~2,360 | 30 | |
| Tomahawk / JDAM / Predator / radar | ~5 | ~1 | small per-unit, huge in volume |
2. China's control — and the weaponization
- Mining ~70%, processing ~90%, heavy-REE separation ~99%, samarium ~100%.
- Apr 2025: export licenses required on 7 heavy REEs (Sm, Gd, Tb, Dy, Lu, Sc, Y) + magnets.
- Dec 1 2025: entities affiliated with foreign militaries (incl. the US) largely DENIED licenses; military-use requests auto-rejected.
- Nov 7 2025 Trump–Xi deal paused the broad controls for a year but retained the military-end-use denials — the chokepoint stays shut for defense.
This is exactly the condition the Z3 defense_chokepoint model encodes: REE independence is UNSAT until ~2028 (the earliest the domestic Mountain Pass heavy-REE + magnet capacity and allied separation can plausibly close the gap).
3. The domestic/allied response
The same state-circular financing as macro-critical-minerals (MP Materials: DoD as largest shareholder + $110/kg NdPr floor + 10-yr offtake), plus magnet-makers (Arnold, Dura), and the DoD FY26 budget lines — a quasi-nationalized supply build racing the ~2028 horizon. Cross-ref macro-critical-minerals, geopolitics-defense-industrial-base, geopolitics-contested-resource-states.
4. Limits
Per-unit REE figures are estimates (GAO/CRS lineage) — directional, not precise. The pace of domestic/allied capacity is the swing variable; the Z3 model treats ~2028 as the binding date.
Sources: MWI West Point — China's REE weaponization; CSIS — consequences of China's export restrictions; Modern Diplomacy / Karve International on per-system dependency.
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