BRUSSELS — On Greenland’s southern tip, surrounded by snowy peaks and deep fjords, lies Kvanefjeld — a mining project that shows the giant, barren island is more than just a coveted military base. Beneath the icy ground sits a major deposit of neodymium and praseodymium, rare earth elements used to make magnets that are essential to build wind turbines, electric vehicles and high-tech military equipment. If developed, Greenland, a semi-autonomous part of Denmark, would become the first European