主题：【原创】晒一晒严重依赖稀土的美军武器装备(续完) -- 桃源客

But there’s an important backstory: national defense.

Besides green energy, rare-earth minerals are essential in creating weapons. “Smart bombs” that use neodymium-iron-boron magnets to control the direction when dropped from an aircraft, lasers that employ neodymium, yttrium-aluminum-garnet used to determine the range of enemy targets at distances over 22 miles, and neodymium-iron-boron permanent magnets used for sound system components used in psychological warfare are among the many, according to a 2004 USGS paper.

The U.S. Department of Defense is currently in the early stages of evaluating its dependency on these minerals, as well as the potential national security risks, according to a study by the U.S. Government Accountability Office.

The jury is still out on alternative energy. With the advancement of new technology, certain products, such as high-efficiency solar cells, do not even need rare-earth metals. Other renewable energy products, such as wind turbines, can be created without rare-earth minerals, but their use is highly advantageous and makes for a much more efficient process.

“Are they critical to the [alternative energy] sector? It’s hard to say that they have the choke hold on the industry,” said Mark Brownstein, deputy director of the energy program at the Environmental Defense Fund. “These are valuable materials in that they have facilitated a tremendous innovation in some of the basic building blocks of renewable energy and energy efficiency technologies. The continued access isn’t only important to existing renewable energy, but also for future advances.”