Good afternoon
The special nature of REE with defense force application is clearly evident within this article:
DOD is advancing its goal of developing domestic supply chains to ensure continued access to the rare earth materials needed to manufacture the permanent magnets used in important U.S. military
www.defense.gov
LYC gets a mentioned along with MP Materials.
Interestingly, The F-35 Lightning II aircraft requires more than 900 pounds of rare earth elements. Each Arleigh Burke DDG-51 destroyer requires 5,200 pounds, and a Virginia class submarine needs 9,200 pounds. REE involving magnets are used in unmanned aerial vehicles, to generate electricity for electronic systems in aircraft and focus microwave energy in radar systems, they also are a critical part of commercial applications in the United States.
Accordingly to the Department of Defense article, REE are also used in other ways that don't involve magnets. Vehicle-mounted laser range finders, such as those found on Abrams M1A1/2 tanks, make use of rare earth elements, as do their portable counterparts and target designators. Also making use of rare earth elements are; fiber optics communication systems; cerium-polished optical lenses; and sonic transducers used in submarine sonar systems.
The US of A is not going to want to be reliant on China for REE supply. Unless there is a major change in technologies, sure, could happen ... but demand for mine is a given, REE is here to stay for quite awhile yet. rcw1 opinion.
Kindly conduct your own due diligence.
Kind regards
rcw1