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.
B. H. Liddell HartWhile the nominal strength of a country is represented by its numbers and resources, this muscular development is dependent on the state of its internal organs and nerve-system - upon its stability of control, morale, and supply.
B. H. Liddell HartThe higher level of grand strategy [is] that of conducting war with a far-sighted regard to the state of the peace that will follow.
B. H. Liddell HartIt should be the aim of grand strategy to discover and pierce the Achilles' heel of the opposing government's power to make war. Strategy, in turn, should seek to penetrate a joint in the harness of the opposing forces. To apply one's strength where the opponent is strong weakens oneself disproportionately to the effect attained. To strike with strong effect, one must strike at weakness.
B. H. Liddell Hart