ry before the advent of
Napoleon there are no big successful sweeping invasions, no marches
upon the enemy capital and so on. There were wars of reduction, wars
of annoyance. Napoleon developed the offensive by seizing upon the
enthusiastic infantry of the republic, improving transport and mobile
artillery, using road-making as an aggressive method. In spite of the
successful experiment of Torres Vedras and the warning of Plevna the
offensive remained dominant throughout the nineteenth century.

But three things were working quietly towards the rehabilitation of the
defensive; firstly the increased range, accuracy and rapidity of rifle
fire, with which we may include the development of the machine gun;
secondly the increasing use of the spade, and thirdly the invention of
barbed wire. By the end of the century these things had come so far into
military theory as to produce the great essay of Bloch, and to surprise
the British military people, who are not accustomed to read books or
talk shop, in the Boer war. In the thinly populated war region of South
Africa the difficulties of forcing entrenched positions were largely met
by outflanking, the Boers had only a limited amount of barbed wire
and could be held down in their trenches by shrapnel, and even at the
beginning of the present war there can be little doubt that we and
our Allies were still largely unprepared for the full possibilities of
trench warfare, we attempted a war of manoeuvres, war at about the grade
to which war had been brought in 1898, and it was the Germans who first
brought the war up to date by entrenching upon the Aisne. We had, of
course, a few aeroplanes at that time, but they were used chiefly as a
sort of accessory cavalry for scouting; our artillery was light and our
shell almost wholly shrapnel.

Now the grades of warfare that have been developed since the present
war began, may be regarded as a series of elaborations and counter
elaborations of the problem which begins as a line of trenches behind
wire, containing infantry with rifles and machine guns. Against this an
infantry attack with bayonet, after shrapnel fails. This we will call
Grade A. To this the offensive replies with improved artillery, and
particularly with high explosive shell instead of shrapnel. By this the
wire is blown away, the trench wrecked and the defender held down as
the attack charges up. This is Grade B. But now appear the dug-out
elaborating the trench and the de