Some economists argue for the advantages of destruction; however they confuse need with demand. Demand requires not just need but purchasing power. This does not mean printing money: the more money created, the less it is worth in relation to goods and services.
Yes, the destruction of war did make more business for the producers of specific things, but what took place was a diversion of demand to particular products from others. As Hazlitt rhetorically attests:
No man burns down his own house on the theory that the need to rebuild it will stimulate his energies.
Those who support destruction theory forget that supply and demand are two sides of the same coin. They are the same thing looked at from different directions. Yes, there is a need to replace older equipment or machinery, but there is always an optimum rate if replacement and a best time for it.
However, these replacements can only be made with savings or capital accumulation, which war destroys.