There is no other science where judgements are tested in blood and answered in the servitude of the defeated, where the acknowledged authority is the… - Bernard Brodie

Clausewitz to be sure, had gone out of his way to point out that armies even when commanded by Napoleon, had rarely defeated opposing armies of as much as twice their size-thus indicating a certain boundary on the influence not only of morale but also of skill in generalship. And when greatly superior forces were defeated by lesser ones, Clausewitz hinted, it was usually because of as much owing to gross incompetence on one side as to exceptional competence on the other. Let us acknowledge the genius of blunder as well as the genius of correct action! The former appeared at least as often as the latter and has had at least as much influence on history.

Instances of grave tactical blunders are certainly not lacking in the history of war, but it is characteristic of tactical errors that tend to be self-exposing, if not in relation to some theoretical ideal then at least in relation to the best the enemy can do. In the past, it has usually been possible for strong nations to recover from them, even if at a heavy cost in blood and possibly strategic position. Strategic errors may or may not expose themselves in some obvious fashion during the course of a war, or even afterwards, and they are therefore much less likely to damage the reputations of those responsible for them.

In wars throughout history, events have generally proved the pre-hostilities calculations of both sides, victor as well as loser, to have been seriously wrong.