The more closely [the German army] converged on [Stalingrad], the narrower became their scope for tactical manoeuvre as a lever in loosening resistance. By contrast, the narrowing of the frontage made it easier for the defender to switch his local reserves to any threatened point on the defensive arc.

With growing experience, all skillful commanders sought to profit by the power of the defensive, even when on the offensive.

The easiest and quickest path into the esteem of traditional military authorities is by the appeal to the eye, rather than to the mind. The `polish and pipeclay' school is not yet extinct, and it is easier for the mediocre intelligence to become an authority on buttons, than on tactics.

If you find your opponent in a strong position costly to force, you should leave him a line of retreat as the quickest way of loosening his resistance. It should, equally, be a principle of policy, especially in war, to provide your opponent with a ladder by which he can climb down.

The predominance of moral factors in all military decisions. On them constantly turns the issue of war and battle. In the history of war they form the more constant factors, changing only in degree, whereas the physical factors are different in almost every war and every military situation.

If we clear the air of the fog of catchwords which surround the conduct of war, and grasp that in the human will lies the source and mainspring of all conflict, as of all other activities of man's life, it becomes clear that our object in war can only be attained by the subjugation of the opposing will. All acts, such as defeat in the field, propaganda, blockade, diplomacy, or attack on the centres of government and population, are seen to be but means to that end.

Air forces offered the possibility of striking a the enemy's economic and moral centres without having first to achieve 'the destruction of the enemy's main forces on the battlefield'. Air-power might attain a direct end by indirect means - hopping over opposition instead of overthrowing it.