Again this is an environmental measure. And a good one. We can estimate how much oil and coal and uranium we have and compute how much each person on Earth should consume for a decent life and how much energy we have and to conserve for a period of time. After these calculations we can then enact a Procreation Replacement law to get the world wide population within those energy numbers. If we experience many wars in a century indicates that the human population is overpopulation.
War is the ultimate measure of population balance.
Likewise for Vietnam War. And likewise for the disintegration of Yugoslavia. So, enact the worldwide law to freeze human population. Make it a universal law on Earth that only Replacement Procreation and get the population of Earth down from 6 billion to that of 5 billion and see if there exists any trouble spots of military engagements. If there exists military tensions get the 5 billion down to 4 billion and see if the saber rattling and war tensions are gone.