Wars are terrible things, but, as Mill observes, sizeable national economies recover quite rapidly from the destruction and deaths that result. As everyone knows, it would be better, much better, if wars could be avoided as far as is possible, their resolutions being reached by other means; but the damage that war inflicts on a large society is neither extreme nor long-lasting, however individually painful.
Revolutions, on the other hand, are deadly and their effects chronically harmful, as witness France, Russia, China, all countries tragically impeded by social revolutions.
Damage to the simpler capital structure of the society can be regenerated, so long as the much more complicated social, intellectual, and institutional elements are untouched. Roads, bridges, buildings, are all important, but the complexity of a mind, of a communicating body of minds, of an historical tradition carried onwards in such an intellectual order, all this is fragile, easily lost, hard to replace, but immensely powerful, hugely creative of fresh order once energised.