Before a change in policy could be imposed, however, a new crisis in the Balkans threatened a general war. The assassination of the Austrian archduke Franz Ferdinand in Sarajevo (now in Bosnia and Herzegovina) on June 28, 1914, inaugurated five weeks of feverish negotiations, in which France’s role has been much debated. Some historians have accused Poincaré and his supporters of a willingness to go to the brink of war rather than seek a negotiated settlement or use restraint on the Serbs and Russians; Poincaré’s state visit to St. Petersburg at the height of the crisis has been seen as an occasion for a French promise of full support to Russia. A more judicious view is that many French statesmen had long seen the possibility and even the likelihood of a general war, and they suspected that the German government desired such a war; the Poincaré group believed that under these circumstances France could not risk the loss of its allies. French support of the Serbs and the Russians, according to this view, was thus inspired by a calculated judgment regarding French security.

Germany’s declaration of war against France on August 3 produced a spontaneous outburst of patriotic sentiment. Trade-union and socialist leaders, some of whom had been on a governmental list of dangerous subversives to be arrested in case of war, rallied to the colours. A national union cabinet was formed. Parliament, after voting war credits, went into an extended recess, handing over the conduct of the war to the cabinet and the high command. During the initial months the high command made most of the crucial decisions; the cabinet accorded almost unlimited freedom of action to the commander in chief, General Joseph Joffre, assuming that the war would last only a few weeks and that civilian interference would only prolong hostilities.

Joffre’s war plans for an immediate advance across the frontier into the lost provinces of Alsace and Lorraine were suspended when German forces struck through Belgium and threatened late in August to envelop Paris. Joffre managed to blunt the German attack and force the Germans to more defensible positions. The rival armies dug into trench positions that remained largely static until 1918. Meanwhile, the French high command continued to believe that the fate of France would be decided on the Western Front. In 1916 a powerful German artillery attack on the French fortress positions surrounding Verdun lasted from February to June and resulted in 380,000 French casualties (162,000 dead) and 330,000 German casualties (143,000 dead). For the French, the hero of Verdun was the sector commander, General Philippe Pétain.

Joffre was by now under heavy criticism in Paris. Both the cabinet and the Chamber were determined to assert greater control over the war effort, so that the high command’s authority was steadily whittled away. Joffre was finally replaced in late 1916 by General Robert Nivelle. All through 1917, rival factions in the Chamber debated the conduct of the war, backing different generals and threatening cabinet crises. Worse still, morale among the troops reached a dangerous low point in 1917, culminating in serious mutinies that affected 54 French divisions. Pétain, who replaced Nivelle in May, managed to achieve stability by a judicious combination of severity and concessions.

Nevertheless, by autumn 1917 there was widespread defeatism in France and much talk of a “white peace.” The Radical leader Caillaux was prepared to try for negotiations with the Germans; but his chance never came. When the cabinet of Premier Paul Painlevé was overthrown in November 1917, President Poincaré recalled Clemenceau to the premiership. Clemenceau stood for a fight to the finish. At age 76 he still had enormous energy and doggedness, and he infused a new spirit into the country. In March 1918, when the Germans launched a last major offensive in the West, Clemenceau replaced the cautious and pessimistic Pétain with a more attack-minded general, Ferdinand Foch, and persuaded the British as well to accept him as supreme commander. The German drive was checked. On November 11 an armistice was signed in Foch’s railway car near Compiègne.

The victory was won at enormous cost for France. Of the 8 million Frenchmen mobilized, 1.3 million had been killed and almost 1 million crippled. Large parts of northeastern France, the nation’s most advanced industrial and agricultural area, were devastated. Industrial production had fallen to 60 percent of the prewar level; economic growth had been set back by a decade. The enormous cost of the war seriously undermined the franc and foreshadowed many years of currency fluctuation. Even deeper, though largely hidden, were the psychological lesions caused by the strain of protracted warfare and by the sentiment that France could not again endure such a test.

At the Paris Peace Conference in 1919, Clemenceau, as the principal French negotiator, declared that his goal was to ensure the nation’s security against renewed German aggression. He sought, therefore, to reduce Germany’s power in every possible fashion and to surround Germany with strong barrier nations. He knew, however, that France could not dictate the peace terms and that he would have to compromise with the Americans and British, to whom he looked for aid in case of German resurgence. His stubborn advocacy of French demands irritated France’s wartime allies; but his willingness to compromise in the end alienated many Frenchmen, who charged him with sacrificing the nation’s security. The critics—who included Poincaré and Foch—were particularly outraged when Clemenceau abandoned his initial demand that Germany give up all territory west of the Rhine and that the Saar basin be annexed to France. These and other concessions led many right-wing deputies to oppose the Treaty of Versailles when it was presented for ratification in the autumn of 1919. Joining the opposition were the Socialists, who argued that the treaty was too harsh and that democratic Germany should not be punished for the sins of the kaiser. A majority of the Chamber, however, reluctantly ratified Versailles and vowed to assure its enforcement to the letter.