Defense Industrial Base and Critical Mineral Dependencies

China holds 80%+ of tungsten, a critical metal for missiles and bunker busters; rebuilding domestic mining will take decades. Exiger reports 28k Chinese components in US systems. Divergent 3D printing cuts costs. Geran-4 drone components highlight vulnerabilities. New: Tungsten dependency highlighted as a major supply chain risk for US weapons production, especially after Iran conflict depletes stocks.