The U.S. has already launched hundreds of missiles and precision-guided weapons in the escalating conflict with Iran, an air campaign that has consumed billions of dollars in advanced military hardware in just weeks. But a new warning circulating in Chinese and Western media suggests the materials needed to keep producing those weapons may be running dangerously low. Reports from the South China Morning Post and Reuters indicate Washington could have only weeks or months of certain rare-earth inventories available for defense manufacturing if supply…