TURIN, Italy -- As the 20th Winter Games prepare to start Friday, thousands of police are taking to the streets of this northern Italian city to protect the 2,500 athletes and 1 million expected visitors.
Security became an Olympic obsession in 1972, when Palestinian terrorists killed 11 Israeli athletes and a German policeman at Munich's Summer Games. The bombing of Atlanta's Summer games in 1996, which killed one woman, and deadly terrorist attacks around the world since 9/11, have only heightened worries.
These games coincide with violent protests by Muslims in European and Middle Eastern cities over caricatures of the Prophet Muhammad published first in a Danish newspaper and again recently in other European publications, including La Stampa, an Italian daily. Continuing threats of retaliation have raised some fears that Muslim radicals might try to disrupt the Olympics.
Other security concerns exist, too.
Al-Qaida sympathizers have threatened repeatedly to attack Italy because it is part of the U.S.-led military coalition in Iraq. Anarchists, anti-capitalists and radical environmentalists have vowed to disrupt the Olympics to protest its American corporate sponsors and the construction of a high-speed rail line between Italy and France.
"It is a very vulnerable time in Italy when it comes to precariously looking in the eye of a number of threats ... from the Olympics, to the construction of the (train) tunnels, to upcoming elections," says Joe Peters, a former Pennsylvania deputy attorney general whose company, MSGI Security Solutions, works with the Italian government on security matters.
"Each of those things individually can produce uncertainty and, therefore, vulnerability that a terrorist would try and take advantage of," he says. "But when you have all three of them intersecting, it presents an interesting challenge."
In security circles, Italy has long been considered a prime terror target. After last year's terrorist bombings in London, Italian authorities deported Turin's leading imam, Bourqi Bouchta, for his ties to terrorism, says Lorenzo Vidino, author of the book "Al Qaeda in Europe: The New Battleground of International Jihad."
"He was the most visible face of radical Islam in Turin," Vidino says. "It was interpreted mostly as kind of a message that the government was sending to the Islamist community in Turin -- 'Don't try anything stupid, or we will evict you.'"
Of eight Italian detainees in the U.S. terrorist prison at Guantanamo Bay, two are from Turin.
Vidino, an Italian terrorism expert for the U.S.-based Investigative Project, says al-Qaida prefers high-profile attacks. He believes it may be deterred by the Olympics' enhanced security.
"The way terrorism in Europe works right now is that it is less structured, more based on independent groups, more spontaneous, less sophisticated," he explains. "These groups look for easier targets. Look at the attacks in London. They know that the Olympic events are very difficult to target."
Yet, Vidino remains concerned: "Every night, there are going to be concerts in downtown Turin. I am sure that it is going to be secure, but it still makes it kind of dangerous."
Protest groups have vowed to mount street demonstrations during the Olympics against a variety of issues -- corporate sponsorships, first lady Laura Bush's visit and a proposed train tunnel through the Alps for a high-speed route linking Turin to Lyon, France -- one group's leader told students at a news conference here. Protesters repeatedly disrupted the Olympic torch relay as it crossed Italy; they plan to renew their protests Friday when the torch arrives in Turin.
"Anarchists pose a threat to many things, especially to something like the Olympics," says Peters, the American security expert, "and there is already a presence of certain groups that are in or near Turin."
At Internet cafes here, customers must register with an identification document before they go online. A posting describes it as an anti-terrorism measure.
Peters says Italians have extensive experience in working to deter attacks by Islamists and other radicals. "The Olympics and Turin will be very well equipped with ground forces, air-space security and border security," he says.
He is working with Italian authorities to use preventive surveillance and investigation technologies during the Games.
In a recent radio address, Italian Prime Minister Silvio Berlusconi called the furor over the Muhammad caricatures "an especially dangerous situation" and "especially close attention will be paid" to its potential impact on the games.
Turin's police prefect canceled a news conference on Olympic security issues Wednesday to attend a National Committee meeting about security in Rome.
Still, Peters is confident the games will not be disrupted.
"I think the Italians will use every arrow in their quiver between now and the Olympics to prevent a terrorist act from occurring," he says.