World War I, we have long been told, was a fait accompli after an assassination. The murder of Archduke Franz Ferdinand, heir to the Austro-Hungarian emperor, by a Serbian nationalist in Sarajevo set into motion a chain of events that would explode into the Great War, a hideous conflict that led to the deaths of millions and redrew the world map. Many countries somberly marked the centennial of the archduke's assassination at the end of June.

But, on Thursday, France marked the centennial of another assassination. On July 31, 1914, socialist leader and intellectual Jean Jaurès was gunned down in a Parisian cafe by a young French nationalist named Raoul Villain (a villainous act, indeed). Jaurès, a pacifist who was deeply opposed to the prospect of war on the continent, had been holding court among a crowd of like-minded socialists. Here's the New York Times news report of the shooting:

They were quietly discussing the day’s events, and M. Jaurès, who was sitting on the ‘‘banquette,’’ had his back toward the rue Montmartre. The window was open, and only a silk curtain hid him from outside view.
Suddenly the curtain was torn away from the outside, and a hand holding a Browning pistol fired two shots point blank at the Socialist leader. Both shots struck him at the back of the head, a little above the ears, one of them blowing his brains out, and M. Jaurès fell forward on the table.

Jaurès is a figure whose place in the French imagination is almost as high as the great 20th century statesman Charles de Gaulle. He was a renowned orator and humanist who deplored the overlapping imperialistic ambitions that were driving Europe's great powers toward conflict. He delivered speeches before tens of thousands and was trying to organize a general strike of workers across Europe against the conflict. On the eve of the war, he expressed his profound opposition:

What will the future be like, when the billions now thrown away in preparation for war are spent on useful things to increase the well-being of people, on the construction of decent houses for workers, on improving transportation, on reclaiming the land? The fever of imperialism has become a sickness. It is the disease of a badly run society which does not know how to use its energies at home.

The French entered the war just days after Jaurès's death.

On Thursday, French President Francois Hollande and others laid a wreath at the cafe where Jaurès was shot. Hollande said the socialist's legacy was "peace, unity and the coming together of the republic." Hollande, like other French politicians from both the left and the right, has tried to trade on Jaurès's aura. But it has so far backfired for the deeply unpopular French president: During an April visit to the town where Jaurès is buried, Hollande was jeered by local residents. 

Jaurès's murderer was inflamed by the dangerous spirits of that time. Many in France wanted to avenge the disaster of the Franco-Prussian War in 1871, which saw the French lose a significant chunk of its territory. Jaurès abhorred the hatreds that underlay nationalism. In a speech delivered in 1911 on the work of the Russian writer Leo Tolstoy, he articulated his socialistic worldview:

In our narrow, confined existence, we tend to forget the essence of life ... All of us, whatever our occupation or class, are equally guilty: the employer is lost in the running of his business; the workers, sunk in the abyss of their misery, raise their heads only to cry in protest; we, the politicians, are lost in daily battles and corridor intrigues. All of us forget that before everything else, we are men, ephemeral beings lost in the immense universe, so full of terrors.

After Jaures's death, those terrors proved all too real.