China controls roughly 90% of global rare-earth magnet processing and dominates supply chains for tungsten, antimony, and gallium — inputs that don't show up as line items in a 10-K but are physically inside the guidance fins, actuators, and armor of American weapons. On December 1, 2025, China's Ministry of Commerce expanded export licensing controls on rare-earth-related items and technology, following earlier 2025 curbs on gallium, germanium, antimony, and graphite tied to the U.S.-China tech and tariff fight. The mechanism is simple: Beijing doesn't need to ban anything outright — a slow licensing queue is enough to stall production lines that run on just-in-time magnet deliveries. For Pentagon primes, that turns a geopolitical lever into a quarterly production-schedule problem, and the exposure is uneven because platform mix, not company size, determines how many rare-earth magnets and specialty alloys go into each unit built.