To foster the people's willing spirit is often as important as to possess the more concrete forms of power.
B. H. Liddell HartThe 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.
B. H. Liddell HartIn any problem where an opposing force exists and cannot be regulated, one must foresee and provide for alternative courses. Adaptability is the law which governs survival in war as in life ... To be practical, any plan must take account of the enemy's power to frustrate it; the best chance of overcoming such obstruction is to have a plan that can be easily varied to fit the circumstances met.
B. H. Liddell HartAir 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.
B. H. Liddell Hart