With its newly arrived forces from the eastern front, Germany enjoyed superiority in numbers on the western front for the first time since the earliest days of the war. Nonetheless, all sides, including Germany, were exhausted. Their strength was limited, and fresh troops from the United States would soon be ready to join the fight on the Allied side. If Germany was going to somehow win the war, now was the time.
Germany therefore poured all of its remaining resources into a massive offensive that began in the early morning hours of March 21, 1918. The goal was to push across the river Somme and then on to Paris. Like most land battles in World War I, the offensive began with a prolonged artillery barrage. In this case it lasted for five hours and included a heavy concentration of poison gas shells along with the usual explosive ordinance. When the German troops moved forward through a combination of heavy fog and poison gas clouds, visibility was near zero, and soldiers on both sides were largely unable to distinguish friendly from enemy forces. By midday, the fog had lifted, and a furious air battle took place over the soldiers’ heads while the Germans relentlessly pounded the Allies.
As the Germans surged forward, they brought with them the newest long-range artillery cannons developed by Krupp, which enabled them to fire accurately upon Paris from the astounding range of seventy-four miles. On March 23, these shells killed more than 250 unsuspecting Parisians, who were baffled because they initially thought the blasts were coming from the ground. The long-distance German shells killed hundreds more in the following days. On March 24, the Germans raced across the Somme, having captured the bridges before the French could destroy them. On March 25, the Allied front broke at precisely the point where the French and British troop lines met.
German momentum continued for another five days until a British advance halted the Germans at Moreuil Wood on March 30. The Allies pushed the Germans back for several days more, until the initiative was turned around once more at the Battle of Lys, which began on April 9, 1918. At Lys, the British and French began to lose ground once more, and the Germans recaptured places (such as Passchendaele and Messines) that the Allies had won in hard-fought battles the previous year.
By the end of the Battle of Lys on April 29, the German army, despite its run of recent success, saw morale at an all-time low. The French and British were in almost as bad a state. During this period of the war, whenever either side launched an offensive, it would only last a few days before the troops ran out of energy and began to fall back. Nonetheless, neither British, nor French, nor German leaders would give up, so the war continued in this way for much of the summer.
Only the United States, it seemed, held the power to shift the balance, but more than a year had passed since the U.S. declaration of war, with little tangible result. Although hundreds of thousands of American troops had been transported to Europe, very few of them had actually participated in combat.
Britain and France wanted the U.S. troops to be integrated into their own armies and sent to the front to fight, but the U.S. government insisted that its troops would fight only as an independent army under U.S. commanders. Because this setup would take a long time to organize in an overseas environment, the policy drew bitter criticism from the French and British, who were still fighting the brunt of the war. The official U.S. entrance into the war in 1917 had given the Allies hope in the face of Russia’s exit. But in light of the slow pace of actual U.S. entry, many in France and Britain feared that they might lose the war before the American troops ever fired a shot.
At a meeting of the Supreme War Council of Allied Leaders on May 2, 1918, there was a small shift in the U.S. stance. General John J. Pershing, the commander of American forces in Europe, agreed to a compromise, pledging to send 130,000 troops that month and several hundred thousand more in the coming months to fight on the front with the French and British forces. This commitment mean that roughly one-third of the American forces present in Europe would see action that summer. U.S. leaders estimated that the rest, however, would not be organized, trained, and ready to fight until the late spring of 1919.
Although Russia was fully out of the war, much unfinished business remained in the territories along the old eastern front. On May 7, 1918, Romania signed a peace treaty with the Central Powers, giving up control of the mouth of the Danube River along the Black Sea coast. At the same time, German troops advanced to the southeast, through the Ukraine, southern Russia, and on to the Caucasus region. The Bolsheviks still did not have an effective hold on this region, so the Germans were able to proceed largely unchallenged.
On May 12, Germany and Austria-Hungary signed an agreement to share in reaping economic benefits from the Ukraine. Barely a week later, however, Austria-Hungary experienced the first in a series of mutinies in its army, carried out by nationalist groups. The first mutiny involved a group of Slovenes; almost as soon as it was suppressed, other mutinies broke out, led in turn by Serbs, Rusyns (Ruthenians), and Czechs.
During the summer of 1918, an unusually severe strain of influenza spread rapidly around the world. Although influenza was not normally associated with high mortality rates, this strain was especially virulent, and it would eventually kill millions of people.
The cause of the outbreak is unknown, but the war was most certainly a contributing factor. First, the war encouraged large-scale movements of people back and forth around the globe, which accelerated the spread of the virus. Second, it is thought that the numerous war-ravaged regions of the world experienced poorer nutrition and less sanitary conditions, leaving their populations especially susceptible.
At the same time, the spread of the disease directly affected the war itself. All sides lost soldiers to the flu outbreak, but Germany and Austria-Hungary were hit especially hard, with the armies of both countries becoming severely weakened just as the Allies were beginning to take the offensive. The epidemic continued well into 1919, when it suddenly died out just as quickly as it had started.
By the end of May 1918, several thousand American troops had appeared on the front ready to fight, arriving just in time to meet the latest German offensive. The U.S. forces were involved in several battles, most notably at Cantigny, on the Somme. Here, 4,000 American soldiers attacked German forces on May 28, while the French provided cover with tanks, airplanes, and artillery. They successfully liberated the town of Cantigny and then held the line during three successive days of German counterattacks. U.S. forces suffered over 1,000 casualties during the engagement.
Throughout June and early July 1918, the Germans attempted a series of offensive actions, still trying to break through the Allied defense lines in France. The lines held, however, in part due to the newly provided American reinforcements.
On June 3, a German attack at Château-Thierry was stymied by intelligence that the Allies gained from German prisoners of war. Knowing of the German plans in advance, the French created a false front line, complete with trenches. The German artillery barrage ended up landing on a set of trenches that were largely empty, and when the German soldiers rushed forward, they found themselves facing mostly fresh and unfazed Allied soldiers who opened fire upon them, leaving the Germans in disarray. Nonetheless, the Germans continued the attack over the next two days, once again threatening Paris.
The Allies responded on June 6 with a counterattack of their own, using combined forces from France, Britain, Italy, and the United States. The attack was devastating, killing over 30,000 German soldiers in twenty days. Although the battle continued for many weeks, the Germans’ will to fight was shattered, and Kaiser Wilhelm II knew that the end was looming. German troops were losing ground every day, and the Allies intensified their attacks with every opportunity. The momentum stayed with them, and they steadily drove the Germans back during all of August and September.
In the Near East, meanwhile, the tide had turned in the war with the Ottoman Empire since the devastating British defeats in Gallipoli and Mesopotamia back in 1916. Since then, Britain had captured Baghdad along with all of Mesopotamia. Farther south, on the Arabian Peninsula, revolts by desert tribesmen had broken Turkey’s long-lasting grip on the region.
In December 1917, the British captured the city of Jerusalem in Palestine and slowly began advancing toward Turkey proper. Finally, on September 19, 1918, the British launched a direct attack on the Turkish front at Megiddo and won a major victory that forced the Turks into a full-scale retreat. By mid-October, Turkey was asking for peace terms.
Although this final period of major combat saw two major developments—the Russian exit and the U.S. entrance—the degree to which these events impacted the war is debatable. By the spring of 1918, both sides’ armies were exhausted from years of fighting and had little reason to hope that an end would soon come. While there were some hints of peace discussions late in the summer, the political and military leaders of all the remaining warring countries were actively planning combat operations intended to last well into 1919.
Russia’s exit from the war gave the Germans a renewed hope of achieving victory, just as the appearance of American troops in Europe gave similar hope to the French and British; however, neither of these events really turned the tide. Rather, they effectively balanced each other out, while the catastrophic influenza outbreak placed a heavy burden on both sides. Ultimately, the real trigger for the end of the war appears to have come from the mass mutinies within the Austro-Hungarian and German militaries.