Italy is taking no chances. Watching for any signs of trouble, military choppers are up over the Alps, monitoring Olympic sites.
Down below, elite Alpine troops patrol as Army paratroopers sweep venues such as the ski jump for bombs.
Italy has deployed 10,000 security forces, although U.S. and Italian intelligence officials tell NBC News that so far there are no specific threats, and that the most likely disturbance would come from radical environmentalists who are demonstrating to oppose a high-speed rail line through the Alps.
But the biggest threat might not be here in the mountains, but in the cities. Italian officials worry about a possible al-Qaida attack on Olympic stadiums, churches and, above all, the public transport system.
Even though Italy arrested more than 200 suspected Islamic militants in July 2005, al-Qaida is believed to still have a network of operatives in Milan, Naples and Torino.
"Italy is known as a base for terrorism-related logistical activities, both in terms for source for recruits as well as funding," says Robert Sikellis with Vance International Security Services.
But why attack Italy now? It has 3,000 troops in Iraq and elections in April.
U.S. intelligence worries about a "Madrid scenario" — a high-profile attack designed to oust the pro-U.S. government.
In Torino's Muslim neighborhood of Porta Palazzo, worshippers told NBC that police have stepped up surveillance. But Italy, now operating a security command center in Torino, is not acting alone. Two NATO AWACS monitor the airspace over the games. And in Washington, the U.S. has set up an Olympics Fusion Center, pooling resources from seven American intelligence agencies.
"We're actually looking worldwide for anything that would suggest a potential terrorist threat to the games," says Arthur McKay, deputy chief of the National Counter Terrorism Center.
But intelligence analysts warn that with so much security in Torino, militants could strike softer targets elsewhere in Italy instead.