I believe we both share this understanding, the problems are

1. China controls ~90% today

2. The US will find it difficult to build out because of how dirty and environmentally damaging mining and processing are.

I did see some research last week about a better way to process rare earths, but it is still research and will need to be industrialized.

Regardless, it will take many years (decade+?) to become self sufficient and China is already willing to and increasingly restricting them