Drones hovering overhead, robotic vehicles roaming Olympic venues to search for explosives, high-speed patrol boats sweeping the Black Sea coast - Russian officials say they will be using cutting-edge technology to make sure the 2014 Winter Games in Sochi will be "the safest Olympics in history."
But intelligence analysts and regional experts say an Islamic insurgency raging across the North Caucasus mountains that tower over the seaside resort of Sochi presents daunting threats. Despite the deployment of tens of thousands of Russian troops, police officers and private guards equipped with high-tech gadgetry, the simmering unrest in the Caucasus could put President Vladimir Putin's pet project at risk.
The Sochi games are the first Olympics in history that are almost on the doorstep of an active insurgency whose members could potentially try to "upstage the games with some kind of attack, which would provide a kind of bad PR for the Russian government," said Matthew Henman, a senior analyst at Jane's Terrorism and Insurgency Center in London.
Potential assailants could disrupt the games even with scarce resources, he said, pointing at the recent Boston Marathon explosions, where two shrapnel-packed pressure-cooker bombs killed three people and injured more than 260 in April.
"You don't need an awful lot of expertise to create primitive but largely effective explosive devices," Henman said.
The elder of the two ethnic Chechen brothers from Russia who are accused of staging the Boston bombings spent six months last year in the restive Russian province of Dagestan, which lies about 500 kilometers (300 miles) east of Sochi, about the distance between Boston and Philadelphia. Russian investigators have been trying to determine whether he had contact with local Islamic militants.
Dagestan has become the center of the insurgency that spread across Russia's North Caucasus region after two separatist wars in the 1990s in neighboring Chechnya. Rebels seeking to carve out a caliphate, or Islamic state, in the region have targeted police and other officials in near-daily shootings and bombings.
"The Caucasus poses a threat because the situation there isn't fully controlled," said Alexei Malashenko, a Caucasus expert with the Carnegie Endowment's Moscow office. "It's unclear who could deal a blow, and how and where."
Police, security and medical personnel in Sochi have conducted dozens of drills to train for potential threats. In the most recent exercise at the end of May hundreds of police officers, rescue workers and ambulance crews responded to various emergency scenarios.
"We conduct training to respond to a broad range of terror threats, like explosives at Olympic facilities or an attack by a group of criminals," said Sarkis Pogosian of the Russian Emergencies Ministry's branch in southern Russia. More than 50 such exercises have been conducted in the past 18 months, according to the Interior Ministry.
The drills have highlighted several logistical problems that could make it hard for rescue workers to respond quickly.
Nikolai Vasilyev of Sochi's search and rescue service, who took part in the latest maneuvers, said the exercises have been relatively small-scale and a bigger real-life challenge could prove daunting. He said it would be hard for rescue crews to arrive quickly by road because of Sochi's chronic traffic jams. The few rescue helicopters the service has would be of little help if there were a large number of casualties.
"It would be practically impossible for ambulances and our vehicles to get to an Olympic facility," Vasilyev said. "We can only hope that everything goes forward smoothly."
Vasilyev said authorities need to reserve designated lanes for ambulances and other emergency services, create a network of mobile hospitals near Olympic facilities and remove parking lots cluttering the access to sports venues.
Security always has been tight in Sochi, where Putin has a presidential residence that he uses often and where he frequently hosts visiting foreign leaders.
The government has further beefed up security before the games, which officially begin Feb. 7. It has deployed 25,000 police officers and thousands of other military and security personnel to protect the city, patrol Olympic facilities, screen incoming vehicles and X-ray construction materials for explosives.
The Defense Ministry has sent a special forces brigade of battle-hardened veterans of the Chechen wars and other conflicts to patrol the forested mountains forming Sochi's scenic background.
The government also has spent big on security equipment, providing security forces with drones, robotic vehicles to search for and defuse mines and new high-speed patrol boats.
But Russia's recent history shows that security cordons aren't always effective.
Insurgents in the Caucasus have mounted a number of large-scale terror attacks in Russia. They include a 2002 hostage-taking raid on a Moscow theater in which 129 hostages died - most from the effects of the narcotic gas that Russian special forces pumped in to incapacitate the attackers.
In 2004, militants from Chechnya took more than 1,000 people hostage at a school in the southern city of Beslan. More than 330 people died in that attack, more than half of them children.
There also have been numerous bombings in Moscow and other cities, including attacks at a Moscow airport and on a high-speed rail line to St. Petersburg. In those attacks, the assailants drove long distances across Russia with weapons and explosives, using ruses or bribes to pass through numerous police checkpoints.
Corruption is deeply ingrained in many aspects of Russian society. But Elena Panfilova, the head of Transparency International Russia, a corruption watchdog, said federal authorities will likely make every possible effort to squelch it within the Sochi security force.
"People in charge of security there are aware of the practice, and they will make sure that the personnel there are disciplined in such a way that they wouldn't even think about it," she said.
Endemic poverty and unemployment in the North Caucasus and brutal tactics used by Russian security forces to quash the rebellion have helped swell the ranks of militants. In Dagestan in particular, the rebellion has turned into a lucrative industry, with many of the gangs associated with ethnic and business clans dividing generous federal subsidies and waging turf battles.
After seeing Dagestan slide into violence for years, Putin in January replaced the provincial leader with a Kremlin stalwart. Earlier this month, SWAT teams from Moscow backed by armored vehicles arrested the mayor of the provincial capital on murder charges and flew him out in a military helicopter to dodge his private army of several hundred bodyguards.
The mayor, Said Amirov, had been seen as the most influential figure in Dagestan and the second-most powerful man in the entire Caucasus behind the Moscow-backed strongman in neighboring Chechnya. In a wheelchair for the past 20 years after one of the 15 assassination attempts against him, Amirov had amassed extensive power and wealth, and had been accused by some of links with the rebels.
Some analysts said Putin took a gamble with Amirov's arrest, which could open the door for even greater instability.
"It's risky, and it may have the opposite effect because thousands stood behind Amirov," said Carnegie's Malashenko.
Denis Sokolov, the head of the Caucasus Center of Project Solutions, an independent Moscow-based think tank, said while Amirov's arrest created risks by sharply upsetting the regional balance of power, he and his supporters might try to hunker down.
"The main tactics of Amirov and his clan would be to try to minimize their losses, not to engage in an open confrontation," Sokolov said. "The regional elites who risked such a confrontation would be doomed to destruction."
Malashenko said while the Kremlin has moved to bring Dagestan's local government back under control, security agencies could also try to make informal deals with rebel leaders to make sure they pose no threat to the Olympics.
Doku Umarov, a widely-known Chechen rebel leader, has claimed responsibility for a number of other recent attacks, including a January 2011 suicide bombing at Moscow's Domodedovo airport that killed 37 people and injured more than 180. Since then, Russia has seen no major terror attacks outside the Caucasus. Umarov said last year that he told his men to avoid hitting civilian targets because Russians in Moscow have risen up against Putin in a series of mass protests.
Many militant cells in the Caucasus have become increasingly integrated into local politics and business and could have a vested interest in seeing the Sochi Games go off without disruption.
Still, they are not the only terror networks around.
Henman, the Jane's analyst, said other terror groups - like the Islamic Movement of Uzbekistan, who have trained along the Pakistan-Afghan border- could also plot a strike on Sochi.
Just last week in Moscow's suburbs, Russian security services arrested several suspects with roots in Russia who they said had come from Afghanistan to conduct terror attacks in the capital.
Malashenko said Islamic militants from the Caucasus who have fought alongside Syrian rebels could also come back and try to strike Russia for its support of Syrian President Bashar Assad.
"They are gaining combat experience and getting angry at Russia down there," he said.
The chief of Russia's top KGB successor agency said last week that 200 militants from Russia are fighting alongside Syrian rebels and acknowledged they could be a threat when they return.
Malashenko also warned that organized rebel cells may pose less of a threat than potential "lone wolf" assailants like the ethnic Chechen brothers suspected in the Boston attack.
"Lone attackers like those in Boston are the most dangerous ones," he said.
Isachenkov reported from Moscow.