South Korea’s drive to become a top-four arms exporter by 2030 is exposing a timing problem beneath its recent success: Korean weapons production still depends on foreign materials and processing that will take years to replace.

That gap has become harder to ignore since China began tightening controls on minerals with military uses. Beijing placed specified tungsten products under an export licensing regime in Feb. 2025 and followed two months later with controls on seven medium and heavy rare earths, including samarium, dysprosium and terbium.

Samarium, dysprosium and terbium are used in high-performance magnetsand other components required by