THE FIRST BOMB EXPLODED AT 11:46 a.m., on the Avenue des Champs-Élysées in Paris. The director of the French security service would later say he received no warning of the impending attack, a statement his detractors might have found laughable were the death toll not so high. The warning signs were plain to see, they said. Only the blind or the willfully ignorant could have possibly missed them.

From Europe’s point of view, the timing of the attack could not have been worse. After decades of lavish social spending, much of the Continent was teetering on the brink of fiscal and monetary disaster. Its debt was soaring, its treasuries were empty, and its pampered citizenry was aging and disillusioned. Austerity was the order of the day. In the current climate, no cow was considered too sacred; health care, university tuition, support for the arts, and even pension benefits were all undergoing drastic cuts. Along Europe’s so-called periphery, the smaller economies were falling like dominoes. Greece was sinking slowly into the Aegean, Spain was on life support, and the Irish Miracle had turned out to be nothing more than a mirage. In the smart salons of Brussels, many Eurocrats were daring to say aloud what had once been unthinkable—that the dream of European integration was dying. And in their darker moments, a few of them actually wondered whether Europe as they knew it might be dying, too.