China’s tightening export controls on dual-use materials and strategically important rare earths are beginning to disrupt Japanese industry — including the defense sector.

Chinese customs data tell the sharpest part of the story. Exports of dysprosium oxide to Japan ceased after October 2025, and shipments of terbium oxide ended a month later. No shipments of either material have been recorded since.

The halt matters because dysprosium and terbium — both heavy rare earth elements — are among the most critical inputs for high-performance permanent magnets used in advanced military systems, electric vehicle motors, aerospace applications and industrial robotics.