You neatly covered yourself Tom but the caveat of 'unless you're strong..."No offense but sometimes you have no choice but to carry all that water. I went on a canyon hike today and 12lbs of my 29lb pack was water. For a 3 hour hike. Of course I had the choice of going out or not and there was zero water in the desert for me. And no I did not drink 1.5 gallons in that time frame but I could have.

Military operations are a separate issue, you have no choice but to go out when your told. I have BTDT, and carried a 100lb ruck with 45lbs of water, 40lbs of ammo and 15lbs of whatever else fit. Not including what was carried on me.

I know that the Armed Forces as a whole are now taking a much stronger stance on water intake and heat injury but its still the individuals job to 'hydrate'.