The United States has roughly two dozen people who know how to run rare earth solvent extraction at commercial scale. The Chinese Society of Rare Earths has over 100,000 members. In 2023, American mining engineering programs graduated 162 students. China graduated about 3,000 from 45 programs. Twelve US universities have shut down their mining engineering departments, including UC Berkeley and Ohio State. The Bureau of Mines, the federal agency responsible for mining research and training, was dissolved in 1996. Chinese pricing drove Western rare earth operations out of business through the 1990s and 2000s. The people who knew how to run those plants retired, changed industries, or died. Rare earth separation requires understanding how 17 chemically similar elements behave across hundreds of interconnected mixer-settler stages over months of continuous operation. That knowledge is accumulated through years of hands-on work in facilities the West stopped running. The average US mine worker is 46. 221,000 are expected to retire by 2029. Building an entirely new critical minerals supply chain means rebuilding the workforce that was eliminated a generation ago. The operational knowledge only comes back by running real plants.