FLORENCE

AS TENS OF THOUSANDS of anti-globalization activists began converging on the European Social Forum on November 7, you could see small trucks trundling panes of corrugated steel and aluminum sheeting towards the center of Florence. Walking through the Piazza della Repubblica, you could hear the zheem! zheem! of air wrenches riveting these barricades onto shop-fronts and department store windows. New Louis Vuitton and Fendi boutiques, scheduled to open days previously, had delayed their grand openings, and were totally encased. The McDonald's on via Cavour dismantled its plastic logos and put them in storage before battening down the windows. Shell gas stations outside Florence did the same.

The anti-globalist groups were meeting in opposition to three things: "neoliberalism" (as they call capitalism), war (particularly the one they expect America to wage in Iraq), and racism. They claimed to come in peace, in the name of "universal rights and democracy." Clearly, the shopkeepers of Florence didn't take them at their word, and neither did the police and carabinieri. The airspace over Florence was closed. Local authorities were supplemented by eight sharpshooter units, five canine patrols, two frogman squads (to protect the U.S. and British consulates along the Arno), fifteen SWAT teams, five bulldozer units (for destroying barricades), and four helicopters. The suburban Sollicciano Prison relocated hundreds of its inmates to make room for fresh arrests.

Florentines were divided over the event. The city's radical-chic mayor, Leonardo Domenici, welcomed the groups gathering for dozens of seminars and workshops in the city's Fortezza da Basso, even when attendance grew from an anticipated 10,000 to nearly 40,000. Nor was Domenici fazed when it looked like an anti-American peace march scheduled to close the week's events on Saturday would draw similarly unexpected crowds. The Nobel prizewinner and longtime Communist Dario Fo was also delighted; he offered the gathering's kickoff speech. The filmmaker Franco Zeffirelli, who has moved increasingly rightward over the years, called the gathering "disgusting." And writer Oriana Fallaci wrote an "Open Letter to the Florentines" in Corriere della Sera, in which she urged her native city to resist the anti-globalists as it had the Nazis.

These differences rested not just on politics but on an assessment of the potential for violence. Since anti-globalization protests first erupted at meetings of the World Trade Organization in Seattle in late 1999, the movement has grown steadily more radical and violent. April 2000 saw 650 arrests in Washington for an anti-IMF protest. At a World Bank meeting in Prague in September 2000, protesters were throwing Molotov cocktails in the faces of police. Dozens were injured and hundreds arrested in Nice in December of that year. In January 2001, police in Davos, Switzerland, used tear gas and rubber bullets to protect an annual conclave of New Economy gurus. Two hundred injuries resulted in Naples in March 2001, and a protest in Göteborg, Sweden, three months later led to 96 arrests. The Göteborg event also showed how scrupulously such events were being policed: 56 cops but only 3 protesters were seriously injured.

But it was at a meeting of the G-8 countries in Genoa, Italy, in July 2001, that the anti-globalists ran riot. The conference began with a series of letter bombs and continued with an unruly "march of the migrants." A day into the conference, wildly violent demonstrations against the police left 700 injured; in the worst incident, rioters in balaclavas and motorcycle helmets chased a police Land Rover into a narrow alley off the central piazza Alimonda. The police, panicking, drove their vehicle into a wall. Protesters leapt onto the Land Rover, bashed in the windows, and began attacking the police with crowbars and clubs. One of the masked attackers, a 23-year-old radical named Carlo Giuliani, picked up a fire extinguisher and tried to stave in the back of the vehicle. A young policeman, already bleeding from a head wound, shot Giuliani in the head, killing him.