Can you tell us how they were to predict the actual amount of casualties that were to occur before they went in?
And once in, with the casualty rate exceeding all estimates, are you suggesting they should have withdrawn?
Yes.
There was NO place to hide. Once it was determined fighter strength was too overwhelming, we should have re-grouped, reassessed enemy strength, then either blasted the Japs to Kingdom Come, OR skipped it.
Iwo wasn't essential -- it was a convenience.