What will the US defense industry do when China cuts off rare earth supplies?

China has spent decades building the supply chains for rare earths and other critical materials into a weapon aimed directly at U.S. supply chains…The Chinese strategy is based on a harsh calculus: Depriving only defense contractors of rare earth supplies will drive costs and production lead times up for the U.S. military and cause concern within the U.S. government, but it will not lead to widespread public discontent.  Jeffery A Green