> The same resources could have been used to further spaceflight, AI, public health, peace, or the environment in or outside of public spending. Warfare is a hellish waste.
It's by no means perfect, but military spending has greatly benefited spaceflight, AI, public health (aid after disasters, advanced prosthetics), etc.
While this is but that only looking at one part of the coin, its very hard to say what outcomes would have happend if these resources were allocated diffrently, either by markets or some other governemnt programm.
The hole idea that 'lets make war and we will probebly get some side benefits out of it' is not substainable, we could have any arbitrary goal and dumb money on the problem and we will get side benefits.
As a minor example we might mention the Internet, which basically grew out of projects funded by DARPA. DARPA by the way was originally started up by Eisenhower, who someone mentioned in another comment.
It's by no means perfect, but military spending has greatly benefited spaceflight, AI, public health (aid after disasters, advanced prosthetics), etc.