Of course it isn't. Replacing a broken window with a new window is almost entirely a waste, perhaps other than making sure the window industry remains marginall

Of course it isn't. Replacing a broken window with a new window is almost entirely a waste, perhaps other than making sure the window industry remains marginally more viable. Much military spending has direct value as surplus goods, scientific advancement, humanitarian support, and patronage for domestic skilled industry. Maybe those benefits, and others, do not justify the expenditures in all cases, but it's far from a "perfect" waste of economic output.