That just makes things worse. Imagine if most people working on nuclear reactors in the navy instead spent the time building and maintaining civilian equipment. The kind of people designing and building the F-22 etc where capable of more long term useful activities etc.

The US could be safe spending 1% of its GDP on defense and largely importing foreign weapon system designs for local manufacturing. There’s clearly a lower limit, but half of current spending is perfectly reasonable starting point before decisions get tricky.