Loren....Thank you for beginning this thoughtful discussion. Without getting into too much science, history or politics, it's only been in the last decade or so (1990's was the decade of the brain) where the FMRI has become a scientific method of understanding brain growth, development and capacity. We now know that our adult brains are still creating/connecting pathways to the Pre/Mid Frontal Cortex well into our 20's. Attitudes and Laws about when children should be considered adults may take years or even decades!
Here is a question to consider. If children become adults at 25, who will fight our wars? Reasonable, rational, and thoughtful people may reconsider the impact violence has on other people, including family and themselves! What about mediation, reconciliation, and compromise as a pathway to solving problems, utto..no more war machine......unless we institute the draft...