Still, the difference in potential outcomes for humanity are substantial. For sure one will only ever achieve blowing up someone with better precision than before... how exiting!
Deterring war is the greatest way to unlock human prosperity.
And killing with precision means saving lives, the greatest good in the world.
Investing in healthcare, education, and infrastructure on a global scale would a) be possible with that kind of budget and b) do a lot more to prevent war, since there would be a whole lot less to fight about.