The Eastern Front would move to center stage in 1915. Although the German Chief of Staff, General Erich von Falkenhayn, was convinced of the primacy of the Western Front, he had been pressured by forces within the German military and political hierarchy to amend his plans and send reinforcements to the east where the twin stars of Generals Hindenburg and Ludendorff were firmly in the ascendant.
The Eastern Front had been frozen during the depths of winter and, although the fighting had slowed in pace, the minds of the staff officers were racing as they planned their next moves. Ludendorff, working in cooperation with the Austrian Chief of Staff, General Franz Conrad von Hötzendorf, agreed a program for offensives by the Austrians in Galicia and the Germans in East Prussia. These were planned to take place almost simultaneously in order to maximize their impact, and had the ambitious overall intention of forcing the Russians to evacuate central Poland or run the risk of being cut off.
The Russians were also still engaged in an increasingly bitter debate between those who considered they should concentrate on the Germans in East Prussia or Silesia and those who advocated a renewed offensive in Galicia and the Carpathians in an attempt to knock the struggling Austro-Hungarians right out of the war. It was no coincidence that one of the main advocates of the former approach should be General Nikolai Ruzsky, commanding the Northwest Front, while the other faction was led by General Nikolai Ivanov, who commanded the Southwest Front. However, the Russian plans would be rendered redundant when the Germans struck first.
For the Germans the campaign of 1915 opened with a characteristic episode. Ludendorff decided that there should be another attempt in the central plains of the Vistula, so at the end of January, IX Army attacked near Bolimów, using gas: its first appearance in the war. The attack went wrong: gas blew back on the Germans, and the cold weather ensured that it would in any case be ineffective. The Germans were sensible enough to break off their attack when it failed. The Russians counterattacked. Command failed to keep in touch with troops; there was no coherent plan, little training, only a mad persistence. 40,000 men were knocked out in three days.
Ludendorff launched the Second Battle of the Masurian Lakes with a two-pronged attack by the Tenth Army in the north and the Eighth Army in the south, both driving in on the flanks of the Russian Tenth Army which was occupying defensive lines in East Prussia, wedged neatly between the sea and the Masurian Lakes. Initially the Russians were taken by surprise. The German forces massed on both flanks, then drove forward seeking to choke off escape routes and achieve another battle of annihilation. They were at least partially successful, but the Russians soon began to fall back, and it was difficult for the Germans to maintain their momentum in such awful conditions.
Following an unsuccessful siege of the Osowiec Fortress, the German attacks pressed east into Russia to try to create a buffer zone. However, in March the Germans withdrew to their own borders under heavy pressure from the Russian Tenth and Twelfth Armies. The grander aim of forcing Russia to abandon the Vistula line had not been achieved, and the accompanying Austro-Hungarian offensive failed.
The Austrian contribution to the winter offensives had actually begun earlier when Conrad ordered forward his troops, assisted by a joint Austrian-German Südarmee group. It was a bold, some might say suicidal scheme, launching a series of attacks to secure control of the passes of the western and central Carpathian Mountains in the freezing cold of January. It was also intended to push deep into Galicia and relieve the besieged fortress town of Przemyśl. A further flanking attack was to be made to the east into Bukovina.
The Russians counterattacked, and for the Austrians the situation deteriorated still further, although the Russians too would be stymied by the horrendous conditions, with the casualty figures on both sides ballooning through the multiple effects of exposure and rampant frostbite. By March, the fate of Przemyśl was beginning to dominate Austrian thoughts. The garrison had launched occasional attempts to break out, which had been easily fended off by the Russians. But at last the stores began to run out and, with no hope of relief, the garrison finally surrendered.
With the fall of Przemyśl, Ivanov was finally allowed to launch a major offensive on the Southwest Front designed to capture the Carpathian passes and finally defeat the Austrians. The offensive was not without its problems, with the Russian Generals in disagreement on how to proceed. A further problem was the spring thaw, which brought flooding and rendered impassable many of the mountain passes. The Russian Carpathian Offensive was eventually suspended in early April.
In the end, Falkenhayn had been right: the winter offensives had been foolhardy. The Russian offensives had also failed to produce results. Grand Duke Nicholas opposed any further attack on East Prussia ‘where we should simply be exposed to the East Prussian railway network’. After the Carpathian campaign, it became clear that the Austro-Hungarian army could only survive with German help.
The imminent collapse of Austria-Hungary left Falkenhayn with no choice but to accede to the piteous demands for reinforcements emanating from the Eastern Front. This was entirely against his own inclinations to concentrate on the Western Front. However, he was determined to retain some strategic control of what was going on, resisting the idea of simply passing the divisions to Hindenburg. The next German offensive, in the Gorlice-Tarnów sector, was intended to be a local limited offensive but it became the Central Powers’ main offensive effort for 1915. In the end the Russian Army, defeated, had to withdraw far into Russia.