Interior lines.
The importance of interior lines to forces superior on the whole in point of numbers has been frequently demonstrated in practice, and never until a few years ago disputed in theory.
The preservation of these lines has led to some of the most memorable achievements recorded in the history of war. It was by means of an interior line that the
Consul Nero was enabled to cut off Assumable upon the Metaurus with the forces he was leading to the succor of his brother Hannibal, and thus render all the victories of that great commander a nullity.
It was by means of interior lines that the great
Frederic was enabled to resist the combined power of
Austria,
Russia, and
France, defeating their armies one after the other, and never allowing them to unite.
These three powers invaded his dominions from three-quarters of the compass — the Bast, the
North, and the
South.
With a vastly inferior force on the whole, being placed in the centre, his marches were shorter, and he could prevent their uniting.
He attacked each of them in detail, and was thus enabled on every field to present a force not greatly inferior.
Had he waited for them to unite they would easily have overwhelmed him.
A magnificent development of the use to which internal lines can be put, occurred in
Bonaparte's first campaign, in
Italy, in 1796.
He was engaged in the siege of Manitus, which was held by 15,000 men. He had but 30,000, all told, to maintain the siege, and drive off the forces that might attempt to relieve it. He placed a certain number of men around the city to keep up the siege.
He distributed the others at convenient points, so that they could keep the enemy in check long enough for him to reinforce them.
He placed one body behind the Adige at Segnano, where the strait road crossed to Manitus.
He placed another higher up, at
Verona, where he had his headquarters.
A third was stationed still higher up on the same river, at
Rivoli, where the mountain comes sheer down upon the stream, and the lake on the other side washes its foot.
He stationed a fourth at
Brescia, at the point of the lake, where the road branching out from the
Rivoli road comes around the water.
As soon as the enemy approached any of these outposts be was apprised of it, and having first discovered which was the real point of attack and which the false, he concentrated his whole force and attacked the enemy, who was obliged, from the nature of the country, to divide his own. In this way he repelled four separate attacks made in five months, and utterly destroyed the armies that made them.
In 1814, in Champaigne, he repeated this series of manœuvres, and by means of an interior line was enabled with 70,000 men to keep at bay, and often defeat, armies numbering 400,000.
In the opinion of the
Duke of
Wellington, he would have destroyed the whole of them, had he not made the march to the enemy's rear, and thus enabled him to march to
Paris without opposition.
It must be recollected that he depended on
Marmont to defend Parish, while he attacked the Allies in the rear, and that that traitor gave up the city as soon as the enemy made his appearance.
The
Duke of
Wellington's defence of
Portugal depended on the same principle.
His lines of operation were interior.
His army was distributed in such a manner that it could all be rallied on any one point in sixty hours. The
French, on the contrary, were distributed over a country four hundred miles square, and their line of operation was exterior, and therefore presented insuperable difficulties, when combined operations were desirable.
For that reason, although they were greatly superior to
Wellington in numbers, they never could rally a force greater than his upon one field of battle.
The advantage of numbers was neutralized by the disadvantages of position.
The Polish General, Skrznecki, gained all his victories in the
Polish Revolution of 1821 by means of interior lines.
It is highly probable that, had he pushed his advantages as he should have done, he would have annihilated the whole
Russian army, but in an evil hour he hesitated, and was lost.
His excuse was, that the attempt was hazardous, and that
Poland had only that army.
He should have reflected that every day's delay strengthened the Russians, and that by hesitating he was rendering his own destruction certain, whereas before it was only probable.
The interior line, it thus appears, is the best way to combat superior numbers, advancing from different points, by enabling the whole force of the weaker party, or at least the larger portion of it, to concentrate against the forces of the enemy while still divided, and preventing their ever coming together.
But one thing is absolutely necessary, and that is constant activity, guided by unceasing vigilance.
It will not do to slumber a moment in such a position.
When the army has been concentrated upon a point, it must attack it, otherwise it leaves its rear exposed to the enterprises of the enemy.
An interior line is obviously of no value, unless the forces which by its means attack one point can be brought back rapidly to attack another.
If the enemy be allowed to get possession of it, he can follow the army that has left it, and thus place it between two fires.
The army that would strike right and left, must be incessantly on the alert.
Its blows must be sudden and powerful.
It must never go so far that it cannot draw back.
We were in hopes, when our troops fell back, that they intended to concentrate at the termini of the railroads and water carriage, with the intention of changing the system of ditching, which it seems to us has thus far been productive of great disaster.
It may be that such is the intention now. But we greatly fear the spade.
It seems to have unaccountable attractions for our
Generals.
It is the
Cleopatra (if we may parody old Sum
Johnson) for which they seem willing to exchange the world.
