When nations go to war their probable fortunes, other things being equal, are to be measured in numbers.
Other things being equal, the numbers one party can bring against the other in men, coupled with the numbers of weapons, munitions, and other material, will decide the issue.
But in European civilization other things are more or less equal. Civilian historians are fond of explaining military results in many other ways, particularly in terms of moral values that will flatter the reader. But a military history, however elementary, is compelled to recognize the truth that normally modern war in Europe has followed the course of numbers.
Among the very first, therefore, of the tasks set us in examining the great struggle is a general appreciation of the numbers that were about to meet in battle, and of their respective preparation in material.
More than the most general numbers—more than brief, round statements—I shall not attempt. I shall not do more than state upon such grounds as I can discover proportions in the terms of single units—as, to say that one nation stood to another in its immediate armed men as eight to five, or as two to twenty. Neither shall I give positive numbers in less than the large fractions of a million. But, even with such large outlines alone before one, the task is extraordinarily difficult.
It will almost certainly be found, when full details are available after the war, that the most careful estimates have been grievously erroneous in some particular. Almost every statement of fact in this department can be reasonably challenged, and the evidence upon matters which in civilian life are amply recorded and easily ascertainable is, in this department, everywhere purposely confused or falsified.
To the difficulty provided by the desire for concealment necessary in all military organization, one must add the difficulty presented by the cross categories peculiar to this calculation. You have to consider not only the distinction between active and reserve, but also between men and munitions, between munitions available according to one theory of war, and munitions available according to another. You have to modify statical conclusions by dynamic considerations (thus you have to modify the original numbers by the rate of wastage, and the whole calculus varies progressively with the lapse of time as the war proceeds).
In spite of these difficulties, I believe it to be possible to put before the general reader a clear and simple table of the numbers a knowledge of which any judgment of the war involves, and to be fairly certain that this table will, when full details are available, be discovered not too inaccurate.
We must begin by distinguishing between the two sets of numbers with which we have to deal—the numbers of men, and the amount of munitions which these men have to use.
The third essential element, equipment, we need not separately consider, because, when one says "men" in talking of military affairs, one only means equipped, trained, and organized men, for no others can be usefully present in the field.
Let us start, then, with some estimate of the number of men who are about to take part in battle; let us take for our limits the convenient limits of a year, and let us divide that space of time arbitrarily into three parts or periods.
There was a first period in which the nations opposed brought into the field the men available in the first few weeks for immediate action. It is not possible to set a precise limit, and to say, "This period covers the first six" or "the first eight weeks;" but we can say roughly that, when we are speaking of this first period, we mean the time during which men for whom the equipment was all ready, whose progress and munitioning had all been organized, were being as rapidly as possible brought into play. Such an estimate is not equivalent to an estimate of the very first numbers that met in the shock of battle; those numbers were far smaller, and differed according to the rate of mobilization and the intention of the various parties. The estimate is only that of the total number which the various parties could, and therefore did, bring into play before men not hitherto trained as soldiers, or trained but not believed to be required in the course of the campaign—according as that campaign had been variously foreseen by various governments—came in to swell the figures.
The conclusion of this first period would come, of course, gradually in the case of every combatant, and would come more rapidly in the case of some than in the case of others. But we are fairly safe if we take the general turning-point from the first period to the second to be the month of October 1914. The second period had begun for some—notably for Germany—with the first days of that month; it had already appeared for all, especially for England, before the beginning of November.
The second period is marked for all the combatants by the bringing into play of such forces as, for various reasons, the Government of each had once hoped would not be required. The German Empire might have marked them as not required, in the reasonable hope that victory would be quickly assured. The British Government might, from a very different standpoint, have believed them not to be required, because it regarded the work of its continental Allies as sufficient to gain the common object, etc. But in the case of all, however various the motives, the particular mark of this second period is the straining to put into the field newly trained and equipped bodies which in the first period were, it was imagined, neither needed nor perhaps available.
This second period merges very gradually into the third, or final, period, which is that of the last effort possible to the belligerents. There comes a moment before the end of the first year when, in the case of most of the belligerents, every man who is available at all has been equipped, trained, and put forward, and after which there is nothing left but the successive batches of yearly recruits growing up from boyhood to manhood.
Although Britain is in a peculiar position, and Russia, through her tardiness in equipment, in a peculiar position of another kind, yet one may fairly say that the vague margin between the second period of growth and the third period of finality appears roughly somewhere round the month of June. It will fall earlier with Germany, a good deal earlier with France; but from the middle of May at earliest to the end of June at latest may be said to mark the entry of the numerical factor into its third and final phase.
Let us take these three periods one by one.
The first period is by far the most important to our judgment of the campaign; a misapprehension of it has warped most political statements made in this country, and most contemporary judgments of the war as a whole. It is impossible to get our view of the great European struggle—of its nature in the bulk—other than fantastically wrong, if we misapprehend the opening numbers with which it was waged.
There are three ways of getting at those numbers.
The first and worst way is the consulting of general statistics published before the war broke out. Thus we may see in almanacs the French army put down as a little over four million, the German at the same amount, the Russian at about five million, and so forth.
These figures have no relation to reality, because they omit a hundred modifying considerations—such as the age of the reserves, the degree of training of the reserves, the organization prepared for the enrolment of untrained men, etc. The only element in them which is of real value is the statistics—when we can obtain them—of men actually present with the colours before mobilization, to which one may add, perhaps—or at any rate in the case of France and Germany—the numbers of the active reserve immediately behind the conscript army in peace.
The second method, which is better, but imperfect, is that which has particularly appealed to technical writers. It consists in numbering units; in noting the headquarters and the tale of army corps and of independent divisions.
The fault of this method is twofold. First, that only actual experience can tell one whether units are really being maintained during peace at full strength; and secondly, that only actual experience discovers how many new units can and will be created when war is joined. In other words, the fault of this method (necessary though it is as an adjunct to all military calculations) lies in its divorce from the reality of numbers.
At the end of the retreat from Moscow each army corps of the Grand Army still preserved its name, each regiment its nominal identity. And the roll was called by Ney, for instance, before the Beresina, division by division and regiment by regiment, and even in the regiments company by company; but in most of these last there was no one to answer, and there is a story of one regiment for which one surviving man answered with regularity until he also died. What fights is numbers of living men—not headings; and if five army corps are present, each having lost two-fifths of its men, three full army corps are a match for them.
The third method is that of commonsense. We must deduce from the results obtained, from the fronts covered, from the energy remaining after known losses, from the reports of intelligence, from the avenues of communication available, what least and what largest numbers can be present. We must correct such conclusions by our previous knowledge of the way in which each service regards its strength, which most depends upon reserves, how each uses his depots and drafts, what machinery it has for training the untrained and for equipping them. This complicated survey taken, we can arrive at general figures.
From 'The Opposing Strengths' - A General Sketch of the European War, The First Phase (1915).