The Pentagon study mentioned in the Bloomberg article admits that DOD's primary contractors don't track their use of rare-earths and consider them just another commodity to be obtained on the world market. Planners in industry and government alike are just beginning to plan for politically-driven supply interruptions. Sometimes security cannot be had at any price, as if it were available to any bidder in a free market.
The F-35 STOVL variant just completed a high-temperature test. Rhenium makes it possible for engines to perform at high temperatures without disintegrating. DOD had better be sure that rare earth supplies won't be a problem. Hope is not a method.
Full disclosure: Long put against LMT. No position in UTX.