There's a crap ton of tech in the military world, and the US is generally the most advanced at a lot of it. Both public knowledge (F-22/F-35, THAAD, aircraft carriers) and all the other sorts of crap - satellites/surveillance tech, software (stuxnet), whatever. The arms race never stopped, it's just not about making singularly bigger bombs anymore, because they're plenty big to destroy the whole planet many times over.
The US isn't spending 800 billion a year on nothing.