Re: The only way to do this
Oh yes they are, because we don't make those in the US anymore. Just about every weapons system more complex than a machine gun has electronics in it and it will have boards that have passive components like resistors, capacitors, and so forth on it. If there's a war and the supply of those parts is cut off that's going to be a big problem before long because just in time manufacturing means no one is keeping much stock. If a war lasts for more than a few months there would inevitably be shortages of certain types of passive components.
Could we make those in the US? Sure, but there's a lot of stuff from the mundane like this to the important like batteries to the critical like chips where it is either already a problem (security of the chips) or will become a problem if there's a war and the supply is cut off. We might say "oh well resistors are simple we can set up a factory to make those" but there are gonna be tons of part numbers between all the different types of discretes and all the various ratings so we'd end up with relatively small runs for each to supply the DoD's needs. They'd cost 10x more easily, and since the DoD would be the only customer for US made resistors they'd probably mark them up another 10x just because the DoD is a captive customer and you wouldn't have any competition in for locally made resistors.