War is a mighty economic engine, this cannot be denied.
Isn't that the broken window fallacy writ large?
Yes; WWII was an economic disaster for huge swaths of the world. The US is pretty much the only industrialized country at the time where it wasn't a complete economic disaster, because it was separated by oceans from nearly all the fighting and destruction.
If there's a shootout in a town that ends up with most peoples' windows getting shot out, the one town glazier will make money off of this, even though it's a net-negative for the town as a whole.
I may be misunderstanding but I don't think so. War forces people's hand in terms having to make progress. This is because during progress can be measured in number of body bags returning from the front and the reduction thereof.
Our modern world was born out of scientific advancements made during WW2. Could these same achievements have occurred in peace time? Obviously the answer is yes. However during war, everything becomes accelerated and things that normally would take a long time can happen very quickly.
I agree that paying for scientific progress with human lives is a bad thing.