Année 1917 : le tournant
Following attempts to break through in 1915, the large-scale offensives of Verdun and the Somme did not allow a return to the war of movement, nor did it exhaust the enemy. On the map of Europe, the situation seemed to favour the central powers, who were able to profit from their conquests of Belgium, France and the Balkans, whilst at the same time sustaining the battle on several fronts, thanks to their combined strength and military superiority. On the coast, the Entente ruled, which helped in sustaining its war effort, developing industry and closing the German ports to mass commerce.
After the "bloodbath" of the Battle of Verdun, the German and French high commanders, Ludendorff (Hindenburg's deputy) and Nivelle, were replaced. On the German side, it was a question of stabilising the western front for the year ahead by retreating along the "Hindenburg" defensive line, about 50 km from the battle line. This entrenchment was supposed to save manpower and release the necessary reserves for future offensives along the more vulnerable Italian and Russian fronts. At the same time, the principal offensive was to be carried out on the submarine fleet that was providing supplies to the Allies, a campaign to destroy the whole of the merchant navy. In the French camp Nivelle succeeded Joffre. A hero at Verdun, he was convinced that his method of attacking with support from a rolling artillery barrage was the way forward and hoped to persuade the British to join in the venture by launching their own offensive and by getting the Italians and Russians involved in the venture.
All-out submarine war was declared on the 1st of February 1917. The critical threshold of sinking 80,0000 tonnes of vessels per month was crossed during April. A real obsession took hold of the civilian populations along the coasts and riverbanks - submersibles were spotted in the Thames, at Marseille etc. The "U-Boot" (Unterwasser-Boot, "submarine") was a formidable weapon at a time when anti-submarine combat techniques were yet to be invented. Adopting a convoy system was a useful defence method, but it was only the arrival of the first sonar detectors and improvements in underwater grenades that allowed combat with equal weapons against submersibles. Within a few months, though, the submarine war discovered its limits. Firstly, through the weakness of the submarine fleet itself - 128 units quickly suffered from wear and tear after just a few journeys. But mostly because it was responsible for the United States' entry into the war on the 6th of April. Although they were not yet able to get involved in Europe, the U.S. Navy were able to act immediately in the Atlantic. The enormous armaments programme launched by President Wilson quickly quadrupled the strength of the American merchant navy. Consequently, losses that had seemed critical in April were to become acceptable as the year progressed. Victory on an economic level was to be out of Germany's reach.
The Nivelle offensive, which was the one that would signal victory, began on the 16th of April along a 50 km front between Reims and Soissons. Although involving three armies and the first French tanks, it was to end five days later on the Chemin des Dames. The famous "rolling barrage" was badly timed with the slow advance of the infantry. The tanks were not mechanically up to the job and the Germans were expecting the offensive: 130,000 men were killed for a negligible gain. This terrible failure obliged Nivelle to give way to General Pétain, who set himself the primary objective of re-establishing the morale of an exhausted army that no longer had confidence in its leaders. Mutinies spread from unit to unit, demanding the end of these bloody offensives. By limiting the number of executions - 49 were shot - and improving the living conditions of the troops along the front, as well as at rest, General Pétain secured the loyalty of his men. He drew lessons from the Chemin des Dames, renouncing large-scale offensives, encouraging the British to carry out a series of battles with limited objectives throughout the year along the front of the Somme (Arras and Vimy in April), and later in Flanders (Messine in June), in order to relieve the French lines. In Italy, Orlando, the new Council President strengthened the inter-allied partnership. In the east, the Russian army, despite its two hundred divisions, was paralysed by its logistical failings and undermined by internal problems, which extended as far as the Tsar's guards. The sovereign was isolated. In March the troops found a common cause with demonstrators when the seizure of the Winter Palace forced Nicolas II to abdicate. Kerensky was elected head of the provisional government by the Douma and renewed his support for the Allies.
General Nivelle's hope of seeing an effort from the Russians and Italians to exhaust enemy reserves on their own fronts did not have much effect. Their offensives did not start until the summer and left them in the same perilous position. In Italy, the front appeared to have been consolidated by the latest offensive on the Isonzo on the 23rd of August. But a counter-attack was carefully prepared to take advantage of the breaches that had appeared in the Italian operation. The Austrian army, reinforced especially with German troops, attacked on the 24th of October and completely defeated the Italian army at Caporetto. The mountain passes were breached and the Austro-Germans drove across the plains to Piave. Venice was within reach. Only the lack of reserves on the part of their attackers spared the kingdom of Italy a humiliating surrender. This disaster highlighted the desperate need to reorganise the army and revive the courage of the soldiers through the power of persuasion. The successes of General Broussilov after Galicia were short-lived. On the 1st of July the Russian attack brought some localised success before it died out. The Austro-German counter-attack actually pushed back the Russians as far as Riga. Now soldiers were refusing to go under fire, contenting themselves with passively maintaining the front. These peasant soldiers were won over by the Bolsheviks' simple slogans for "Peace" and "Land". The Eastern Army's French officers noted that the Russians could no longer be counted on. Only the British had regular success against the Turks, with the taking of Baghdad and then Jerusalem. But these events seemed to have little effect in Europe. The depletion of the Belligerants appeared to reach its climax in 1917. The futility of the fighting undermined soldiers' morale and the length of the conflict was driving every country to breaking point. In France, talks averted strike movements against rising prices. In Germany, it was mariners of the surface navy who, having nothing to do, who formed a protest group and in Austro-Hungary, problems between the different nationalities threatened to break up the Empire.
However, this situation was more favourable to the Entente, which was supported by a global market and almost limitless American credit. By overcoming this crisis in its fighting spirit, it took the lead in the war of attrition. On the ground, modern armaments were used extensively. The French and British learned to manoeuvre tanks, thus improving their performance. The air force and the D.C.A. (anti-aircraft defence) grew stronger. Although the "Aces" still dominated the skies, the aerial battle was no longer an individual affair. Aircraft operated in groups of several squadrons and their missions became increasingly specialised: chases, reconnaissance, ground attack. There were also attempts at strategic bombardment of enemy towns.
Finally, the destruction of alliances changed the strategic situation. Brought to power by the October revolution, Lenin immediately engaged in peace talks. The end of fighting in the east allowed the central powers to release 120 divisions the following year. Enough to secure victory in France? There was still a lot to do in order to build a large American army. While waiting to train up and arm a good number of its divisions, France enthusiastically welcomed General Pershing's headquarters to Paris. The final decision as to which side would win would be made on the western front in France. Having exhausted all their other battle options, the two coalitions were getting ready, with one side waiting for the Americans and tanks and the other engaging in one last hand-to-hand battle.