Dependence on the railway for the transport of considerable bodies of troops on short journeys—say for twenty, twenty-five or thirty miles—is rendered inexpedient by the fact that, when allowance is made for the time likely to be taken, not only on the journey, but in the assembling at the station, in the entraining and detraining (perhaps at some place devoid of adequate platform or siding accommodation), and in the march from the arrival station to destination, it may well be found that the troops could cover the distance in less time by road, apart from the consideration, suggested above, as to their being in a better position, when marching, to resist attack. Experts in all countries have studied this question with a view to deciding, on the basis of their national conditions, within what limit it would be better for troops to march by road in preference to going by rail.
For reasons akin to those here stated, supplemented by the recent great expansion of motor transport, less has been heard of late concerning the proposed construction in this country of strategical railways along a coast-line remarkable for its sinuosities, and presenting, therefore, an exceptional position from the point of view of coast railways for purely defensive purposes.
As regards long-distance journeys, whilst armies marching by road have often been materially reduced in proportions by the number of men falling out owing to lameness, exhaustion, or other causes, those who reached the theatre of war, representing "the survival of the fittest," were better able to endure the trials and fatigues of the subsequent campaign than if they could have made the journey by rail under conditions involving no strain, but affording them no such exercise and strengthening of their physical powers.[81]
Experience has further shown that exceptionally long railway journeys may have a prejudicial effect upon troops from the point of view, also, of maintenance of discipline.[82]
The services rendered by railways in war relate much more to strategy than to tactics. Great masses of troops and munitions, brought from all parts of the interior, may be conveyed readily and safely by rail to particular points in the theatre of war; but the possibility of effecting their transport by rail from one point to another on the battle-field when the opposing forces are in actual contact is subject to many restrictions and constitutes a much more difficult undertaking.
The imperative need for guarding a long line of railway communications, more especially in occupied territory, may lead to the withdrawal of a considerable number of men from the main army, weakening the strength of the available fighting force proportionately.
D.—Drawbacks and Disadvantages
While, notwithstanding the conditions to be observed and the limitations to be experienced, the balance of advantage conferred by railways on the conduct of war may appear so pronounced, from a military and a political point of view, there is a darker side to the story, as regards the world at large, which must also be taken into account.
If railways have increased the power of defending a country against invasion they have, also, increased enormously the power of aggression at the command of an invader.