We have rare earth deposits here. Was talk of allowing production the last time neodymium prices went through the roof several years ago. It's an environmentally nasty process. We'd just rather screw up China's environment, get it cheaper, and pat ourselves on the back for being "green" instead.
One of the articles Immi linked to specifically cited Russian rocket engines.
A lot of our oil goes on the world market with all the rest. It's not like we keep it all here, though that one might be the easiest or fastest to switch to self-sufficiency.
Whatever increased costs of doing that stuff here be more than offset by getting out of the 100-odd other countries our military is in and not needing near as much of it.
Depending on other nations stuff for your own military when you don't really have to is still a dumb thing to do.
