Selasa 12 Maret 2013 di Washington, Amerika Serikat (AS), Director of National Intelligence (DNI), James R. Clapper, merilis testimoni kepada U.S. Senate Select Committee on Intelligence (komite Senat AS bidang intelijen) : “… rare earth elements (REE) are essential to civilian and military technologies and to the 21st century global economy, including the development of green technologies and advanced defense Systems.” (Clapper /DNI, 2013).
Meskipun Department of Energy (DoE) Amerika Serikat (AS) berupaya menemukan alternatif (misalnya bahan nano) untuk REE, khususnya bahan untuk magnet permanen, namun upaya DoE itu belum berhasil menggati REE (Piesing, 2013). Oktober 2017, ahli REE Linda Wang dkk (2017) asal Purdue University merilis inovasi teknologi ekstrak REE dari limbah ash batu-bara.