But the mother of all contagious uprisings was the wave of revolutionary fervor that swept Europe in 1848. The events of 165 years ago in France, Italy, Austria, Prussia and elsewhere are mostly forgotten by modern Americans, but “the parallels with contemporary globalization are very obvious,” says Nottingham University’s David Laven, author of the forthcoming Restoration and Risorgimento; Italy 1796—1870. The people dying at the barricades were artisans who’d seen their livelihoods taken away by new industries and organizations. They were students whose families had made enormous sacrifices to get them good educations, only to discover the promised jobs were not to be had.

Today, says Laven, there’s the same dislocation, the same glut of education and shortage of employment in many of the countries experiencing unrest. “Without the right connections you stand not a hope in hell of getting a job in Italy or Greece,” says Laven. People start to revolt, he says, when they feel they’ve been done out of “something they thought was their right.”

When governments hesitate in the face of confrontation, unsure whether to institute reforms or smash their opposition, the effervescence grows. “Revolutions take place when there is sufficient repression to create martyrs,” says Laven. “But not sufficient repression to nip the revolutions in the bud.” The proximate causes of rebellions are not so much long-term structural problems, says Laven, but “short-term triggers” that set off explosive emotions.