DEFINITIONS.--Strategy and Tactics have often been treated by non-military writers as if they were independent branches of the soldier's profession, but while they may indeed be separately defined it will be found in practice that they cannot be separately considered. The theatre of operations is the kingdom of Strategy, the province of Tactics is the field of battle, but when the battlefield is reached it so far transcends in importance every other point in the theatre of operations that no _tactical_ end is worth aiming at in preference to striking with all available strength at the field force of the enemy, and this, it will be seen, is the goal of all _strategical_ combinations. "Strategy must ever be striving for Tactical success; Tactics must ever keep in mind the Strategical situation and must constantly aim at creating fresh Strategical opportunities. Tactics without Strategy resembles a man without legs; Strategy without Tactics is like a man without arms" (General Sir E. B. Hamley). "To seek out the enemy's armies--the centre of the adversary's power--in order to beat and destroy them; to adopt, with this sole end in view, the direction and tactics which will lead to it in the quickest and safest way: such is the whole mental attitude of modern war. No Strategy can henceforth prevail over that which aims at ensuring Tactical results, victory by fighting" (Marshal Foch).
Local successes on the _field of battle_ often have effects that are felt throughout the _theatre of operations_. Lord Roberts's advance on Pretoria relieved the pressure on Kimberley in the west and on Ladysmith in the east, and these centres are upwards of 300 miles apart. _The { 7} First Battle of the Somme_ (July 1, 1916) not only relieved the pressure on Verdun but held in position large enemy forces which would otherwise have been employed against our Allies in the East. General Byng's surprise attack at Cambrai (November 20, 1917) was followed by a determined counter-attack by the Germans on November 30, which appeared to nullify the results achieved from November 20 to 25; but "there is evidence that German divisions intended for the Italian theatre were diverted to the Cambrai front, and it is probable that the further concentration of German forces against Italy was suspended for at least two weeks at a most critical period, when our Allies were making their first stand on the Piave Line" (Sir D. Haig's Dispatches).