Introduction

Critical minerals have received a surge of attention recently, much of it tied to China’s dominance of extraction and processing and recent application of export controls on minerals with defense applications.  Policy discussions tend to focus on “critical minerals” collectively, but it is important to distinguish those needed for agriculture and transportation from those needed for national security.  Every mineral deemed essential for U.S. national security, economic security, and supply chain resilience and included on the official list of critical minerals maintained by U.S. Geological Survey list is important for its own reasons, but there are a few elements whose looming shortage now borders on an emergency, requiring extra focus from policymakers.  Certain “heavy” rare earth elements are among them.