Today, it isn't easy to imagine our modern life without the 17 esoteric elements known as rare earths. Aside from a growing chorus of defense and policy experts, rare earths are not exactly a topic of daily conversation. But the modern life we now enjoy would be impossible without these elements. Our mobile phones, personal electronics, satellites, and cars simply do not work without them. They are the quintessential material of modern technology. The importance of rare earths in technology likewise applies to high-tech arsenals. Our precision munitions, communications, and almost everything else requiring super magnets and semiconductors are intrinsically tied to rare earth metals. These omnipresent rare earth metals comprise 17 elements on the periodic table; the 15 elements of the lanthanide group, as well as scandium and yttrium, are further classified as light or heavy rare earths according to their atomic weight.

The light rare earths are lanthanum, cerium, praseodymium, neodymium, promethium, and samarium. Heavy rare earths, which are rarer and consequently more valuable, include europium, gadolinium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium, together with scandium and yttrium. The term referring to this new technological holy grail, rare earths, is surrounded by a certain ambiguity. Understanding the different meanings associated with its use is essential to understanding how their supply chain works and their strategic relevance. Whether out of ignorance or a desire to simplify key points for the population at large, both politicians and journalists erroneously use the term rare earths to refer not only to rare earths, but also other 'e~green metals' necessary for the green energy transition, such as lithium, cobalt, and nickel. While these green metals are certainly important for our envisioned green future and are inexorably intertwined with rare earths, we focus here largely on true rare earths, seeking to focus on the details regarding their most interesting secrets, and the devils hidden therein. The critical strategic importance of rare earths is slowing emerging into the public forum, yet for all of their importance their procurement is concentrated in just two countries, China and Australia. Even then, the Asian giant controls 80% of the rare earths market, and if we look specifically at heavy rare earths, these figures nearly reach 100%.