The sheer extent of China’s control over the so-called heavy rare earths such as gadolinium and terbium is staggering. 

The U.S. produces some light rare earths at the Mountain Pass mine in California. But Trump slapped major tariffs on Vietnam, the one country with at least some market share over each rare earth China dominates.

People freaking out about rare earths should listen to this podcast, apparently the imports are really tiny (comparable to US spending on rare pepes) so even if Xi could spike the price like 10x that would still do basically nothing.
https://www.bloomberg.com/news/articles/2025-04-15/javier-blas-on-china-s-rare-earths-metals-dominance

Also a lot of it could be recycled so if Lockhead Martin are having trouble getting the stuff for their fighter jets they just have to go door to door collecting old vacuum cleaners