Rare earth elements -- of which there are 17, including the 15 lanthanides plus yttrium and scandium -- are needed in many industrial and national security applications, from flat panel displays to jet fighter engines. Yet there are foreseeable stresses on the national and global supply of these materials.
"The United States was once self-reliant in domestically produced [rare earth elements], but over the past 15 years has become 100% reliant on imports, primarily from China," a new report (pdf) from the Congressional Research Service observes. "The dominance of China as a single or dominant supplier [...] is a cause for concern because of China’s growing internal demand for its [own rare earth elements]," the report said.
The CRS report provides background and analysis on the uses of rare earth elements, existing reserves, national security applications, the global supply chain and relevant legislation. See "Rare Earth Elements: the Global Supply Chain," July 28, 2010.