While I don't have an opinion on the theory under discussion, I think the way to read into the OP's definition of 'war' is 'total war', which the US has not been involved in since WW2. The 'total war' part is required for the massive culling that the OP seems to think is needed for a prospering society.
You raise a good point, and I have commented in other forums on the strangeness of the US currently fighting large distant wars with a peacetime economy, which is very expensive.
But if that's the case, isn't the argument then an oxymoron? Total war is a total realignment of society - the society is necessarily broken down and forged afresh. Engaging in total war 'to save a society' necessarily changes that society, often quite profoundly. The total war of WWII made massive social changes when comparing pre- and post-war societies (two big ones were end of colonialism and rising equality of women in developed nations). The society you get at the end of total war is different from the one you may have been trying to preserve.
