Why do military theorists,armchair critics, and wargamers think war is easy?

Well, what they often overlook is the fact that hindsight is 20/20. Nobody ever stops to consider that the military commanders who made the original decisions were the first. They didn't know what would happen, and all they can do is hope it works and proves as a lesson to all who come after. When an arm chair tactician comes by and reads about said battle, it's really easy to say, "Well, he should have done this." He can only say that though because he knows the outcome, and what the enemy did whereas the original commander did not.