I'm not sure just how much the US spends on weapon testing, but I imagine it's a bonkers number. And now they get an opportunity to test in a real environment, with some other country's army to do much of the heavy lifting?

I do software dev and testing stuff is expensive. Real world testing is a particularly difficult and pricey thing to do. It's not easy to simulate realistic usage and it's super common to discover all sorts of issues only when something is used outside of controlled conditions. That's why so many web products get the hug of death. It's why Lemmy has had so many problems not just with scaling, but things like UX. It's so easy to not realize even "obvious" problems when you don't have a large number of real users.