U.S. military technologies such as guided bombs and night vision rely heavily upon rare earth elements supplied by China, and rebuilding an independent U.S. supply chain to wean the country off that foreign dependency could take up to 15 years, according to a new report by the U.S. Government Accountability Office (GAO). Both "light" and "heavy" rare earth elements represent a family of minerals found in commercial products ranging from TV displays to cell phones, as well as green technologies such as hybrid electric motors and wind turbines. For example, the rare earth element neodymium is very magnetic and is...