As criticism of its yuan policy temporarily subsides, China is facing a war on a new front: Rare earth metals.

Led by the US Government Accountability Office, voices from the US media and industry recently attacked China's rare earth policies, claiming that the nation's control of rare earth metals, critical in making things from advanced weaponry to hybrid cars, threatened its key industries such as defense.

Indeed, China has imposed export quotas on rare earth metals, because, for one thing, domestic tapping of those metals has been almost out of control, often damaging the environment in rare earth areas. The low prices, meanwhile, cannot match the value of the product.