For more than a decade, the United States has treated rare earth independence as a mining problem. But the real vulnerability is further downstream. That’s where rare earths are turned into metals and become a part of the American military machine and its industrial backbone. That capability largely disappeared from North America, and rebuilding it is far more complicated than reopening a mine. Tim Johnston, co-Founder of Realloys (NASDAQ: ALOY), the only North American company that takes heavy rare earths to the magnet finish line, says…