One cannot approach economic systems rationally without taking into account 1. Increasing population 2. treating the environment as an unlimited source and sink 3. militarism which diverts wealth and causes suffering 4. gross inequities of wealth which result in conflict

Agreed, David F. Supporters of charges on land and natural resources instead of taxes on labour and capital respect the planet. Henry George propounded this as a solution to boom/bust, to poverty, and to war. He argued that as wars are fought over territory and natural resources, if we paid the rent for their use and abuse and were unable to monopolise or 'privatise' natural resources, wars would immediately become obsolete.

If only life was so simple.
I suspect wars are fought not over land or territory so much as ON land and territory. Specialisation could play a far more significant role.
As we specialise, we become more 'efficient'; which is to say we achieve more with less man power -which of course frees up more people to... what?
We could use them to build monuments; at a time when agriculture was being revolutionised, we had Stonehenge, Pyramids and ridiculously large mounds of dirt, and we had war...
We could colonise, -if there was anywhere left to colonise...
and we could have war...
I would suggest revolutions are fought for the reasons David f (and ironically, Karl Marx- “all wars are class wars”) mentions.
Wars are fought because young men have too much time on their hands (among other reasons).

Life is grim, Grim - and simple. People and countries with dollars in their pockets don't have to go to war for resources. They trade in a civilised fashion. The next step is trade wars if we can't solve this financial crisis; then, real war, because the 99% will again use the 1% as the kleptocracy's pawns.