Japan’s increasing military spending and domestic arms production rely heavily on heavy rare earth elements. These elements are essential components in weaponry but generate hazardous radioactive waste as a byproduct. This waste poses a potential threat to public health and environmental safety. The reliance on these materials raises concerns about the long-term management and disposal of the resulting radioactive byproducts. Authorities have not yet detailed comprehensive plans for mitigating the risks associated with this waste. The issue highlights a potential trade-off between national security objectives and public well-being. Further investigation is needed to assess the scale of the waste and its potential impact.