The lessons of the Russo-Japanese War were closely studied, especially by the Germans, who perceived long before their competitors the importance of entrenchments to protect their infantry from artillery fire, and the huge advantage given by mobile heavy artillery. Machine guns had also proved their value, but their rate of fire of 600 rounds per minute presented problems of ammunition supply that made their employment in mobile warfare highly problematic. All armies added them to their arsenals, but it was only in the defensive battles on the Western Front in 1915–17 that they came into their own.
All armies abandoned their colourful uniforms (the British, accustomed to fighting in the dust and desert of colonial campaigns, had done so already) and clothed themselves in various shades of the mud in which they would now have to fight—except the French, who were compelled to retain their distinctive scarlet trousers by nostalgic nationalist politicians, and suffered terribly in consequence. All competed in introducing the new technology of the aeroplane and the automobile, although in 1914 the first was only just coming into use to supplement cavalry reconnaissance, and the second was used mainly for the transportation of staff officers and senior commanders. Throughout the war, transportation and traction beyond railheads were to remain overwhelmingly horse drawn. Once they left their trains, armies could still move no faster than those of Napoleon—indeed, of Julius Caesar. Finally, the importance of wireless communications—and their interception—was generally recognized, especially in naval warfare. But on land sets were still too heavy for operational use below army headquarters, with results for front-line fighting that we shall consider in due course.
In armament all European armies in 1914 were at least comparable. Only in their use of mobile heavy artillery were the Germans able to spring unpleasant surprises. What gave military planners sleepless nights was not the equipment of the enemy armed forces, but their size. This was ultimately determined by the size of the population, but it was also affected by social constraints that limited the extent and duration of conscription, and financial pressures limiting its cost. Of the three powers principally concerned, the population of the newly united German Empire at sixty-seven million exceeded, as we have seen, that of France at thirty-six million, but was far inferior to the 164 million of the Russian Empire.
In France, democratic mistrust of militarism had confined military service to two years, but over 80 per cent of available manpower was called up. In Germany military service lasted for three years, but the numbers called up were constrained by both budgetary considerations and resistance from an increasingly left-wing Reichstag, as well as by reluctance within the army itself to recruiting within the growing and (it was thought) politically unreliable urban population. Only some 54 per cent of the manpower available was called up before 1911, which in 1911 gave the German army a peacetime strength of 612,000 as against the French of 593,000. The size of Russia’s population and in consequence of her army (1,345,000) looked terrifying on paper, but it was made less impressive by shortage of railways to deploy it and the administrative incompetence so humiliatingly revealed by the defeat in 1905. So negligible had the Russian threat then appeared that Schlieffen, in the ‘plan’ he bequeathed in that year to his successor, virtually ignored it altogether and concentrated the entire strength of the German army against France.
The Russian defeat in 1905 may have reassured the Germans, but it terrified the French. After 1908 they began to pour money into Russia to build up her economic infrastructure (in particular her railways) and re-equip her armies in a ‘Great Programme’ of military reform that was due for completion in 1917. It was now the Germans’ turn to be alarmed. They could no longer underrate the importance of Austria-Hungary as an ally, and there was much wild talk in both countries about the Slav threat to Western civilization. The constraints on the Germans’ own military build-up disappeared, and in 1912 they introduced a crash programme of expansion that increased the size of their army by 1914 to 864,000. The French responded by increasing their own length of military service to three years, giving them a peacetime strength of 700,000. In both countries the additional expenditure was rushed through parliaments increasingly convinced of the imminence of a war in which their national existence would be at stake. When war did break out in 1914 the Germans and French each mobilized about four million men, of which some 1.7 million Germans and two million French confronted each other on the Western Front.