The problem for the US is the number of years it actually takes to be able to produce Rare Earths, this is why countries like Australia with companies like Arafura will be in high demand, there's a big gap between digging it out of the ground and being capable of actually producing Rare Earths, something the Pentagon may not understand.

https://www.rt.com/business/464137-pentagon-rare-earths-china/

Pentagon wants to secure supply of rare earths after Chinese threats to cut exports – report

Published time: 14 Jul, 2019 10:45

The Pentagon has been looking into US miners’ capabilities to produce rare earth metals, according to Reuters. It comes after Beijing signaled it may restrict exports of the vital materials amid the trade war with Washington.

The US military has asked miners to come up with plans to develop domestic rare earths mines and processing facilities, an exclusive report, which cites a government document, said. At the same time the Pentagon asked the miners to detail their demand for rare earths.

The Pentagon wants a quick response from the manufacturers and gave them just a few weeks, until the end of July. After a review of the responses, the agency reportedly may then offer financial assistance to support the vital industry.