Mark Koyama believes the economic costs of warfare are usually dismissed, for a variety of reasons:
1. Arguments like: the Romans destroyed Carthage in 146 BC yet by, say, 0 AD Carthage had recovered and was a major economic metropolis.
2. Arguments from analogy: Japan and Germany were devastated by WW2 yet they recovered rapidly and exceeded previous levels of living standards within a decade and a half.
3. Keynesian-style arguments: warfare was necessary to stimulate aggregate demand.
4. A binding technological ceiling on growth in preindustrial economies. Hence in the absence of warfare, growth was limited.