Antimony hardens armor-piercing rounds, sharpens night vision optics, primes ammunition, and lives inside flame retardants, lead-acid batteries, and semiconductors. It is also one of the few critical minerals where China’s grip on the global market translates directly into U.S. defense procurement risk. China, Russia, and Tajikistan together account for roughly 90% of global antimony mine supply, with China dominating downstream refining. In December 2024, China imposed antimony export restrictions specifically targeting the United States. Those restrictions were suspended in November 2025 for a 12-month pause running through November 27, 2026 — but the licensing controls remain in place, and the structural supply problem has not gone away.