The Sochi Olympics have become the "Holy Grail" for terrorists, experts on Russia say, and they don't even have to attack the Games directly to claim success.
"You don't necessarily have to hit Sochi to spoil the Games," says Andrew Kuchins of the Center for Strategic & International Studies. "A series of Volgograd-caliber attacks would virtually terrorize all of Russia."
Last month's attacks in Volgograd, a major transit hub approximately 400 miles (650 kilometers) from Sochi, targeted a train station and a trolley bus and killed more than 30 people.
Juan C. Zarate, former U.S. deputy national security adviser on terrorism, agrees that terrorists have a "clear intent" to disrupt the Olympics and to embarrass Russian President Vladimir Putin.
"The terrorists, for purposes of attacks and embarrassment, don't have to get into the inner rings of security within Sochi to have a declared successful attack," he says. "They need only create a sense of terror or disruption in the immediate environment - or even in the transportation hubs, as we've seen in Volgograd, to create a sense of instability."
The terrorist leader of the self-described "Caucasus Emirate," Doku Umarov, has directly urged his followers to destroy the Games.
Reports are circulating that Umarov was killed by Russian forces but there has been no confirmation and the two experts, who spoke at a CSIS briefing, noted there have been numerous previous rumors of his death.
Umarov, who is believed to be based in Dagestan, a Russian republic located to the east of the site of the Sochi Olympics, has led rebel groups in the south of Russia for years but more recently has claimed alliance with global jihadists.
Kuchins says terrorists threatening the Olympics "are motivated by a global jihadist ideology which is common to that of al Qaeda and others around the world."
He said that's what motivated the Tsarnaev brothers, who authorities allege bombed the Boston Marathon last year. They were also from Dagestan in the Northern Caucasus.
Even if Umarov is dead, he says, it may not make that much difference since he is not primarily an operational leader.
"The network is loose and others might be competing to claim responsibility for terrorist acts," Kuchins says.
Juan Zarate says security concerns are always high for events like the Olympics but the threat in Sochi is "unique." The region is full of terrorists groups including Central Asian ones, like the Islamic Movement of Uzbekistan and the Islamic Jihad Union.
They have a "clear intent and desire to disrupt or embarrass Putin," he says, and they have proven their capability to attack in places like Volgograd, as well as on trains and at airports.
They have "multiple modalities in terms of attack vectors," Zarate explains - a variety of means to attack, including suicide bombers, so-called "Black Widow" female suicide bombers, assault teams, and teams of multiple operatives.
Zarate says reports that Russian security forces are hunting in Sochi for a woman who might be a Black Widow are worrisome because she might be part of a broader series of suicide bombers that have been dispatched to different sites.
Reports like that fuel fear and that is precisely what the terrorists aim to do, says Zarate.
"You could have a relatively minor terrorist attack during the opening ceremonies or something in the general environs," he says. "And it begins to affect the sense of security for the Olympics and, in many ways, the terrorists begin to win in terms of that perception."
Even with an attack in Moscow you might see discussion among the various national teams of the need to withdraw.
"That would be disastrous for the Olympics," he says.
The Sochi Olympics also are being ensnared in the broader scheme of jihadist movements, both Zarate and Kuchins agree.
The original rebel insurgency began in Chechnya in the 1990s and early 2000s, but Zarate says "these groups have been animated and populated by global jihadi actors, many of whom have interacted with the leadership of the Caucasus Emirates, many of whom have gone on to fight, including now, in places like Syria."
And Syria, not just Chechnya, says Zarate, is an important accelerant of terrorism in the Caucasus region of Russia.
"I think it's critically important to keep in mind that the Russians have taken a very open and active role in supporting Assad which has brought back Russia into the center as an enemy for the global jihadi movement," Zarate says.
Recent terror attacks in Russia, he says, have created a "growing sense of lack of confidence in that security, in spite of Russian assurances" and U.S. lawmakers and officials are now more openly voicing worry that Russia is not cooperating on security as much as the U.S. wants.
countries that host Olympics are proud and don't accept offers of security support initially, Zarate explains. But as the event draws closer, they accept it "because of the daunting task of protecting the Olympics."
But that doesn't appear to be happening with Russia, he says.
"I think the reverse is happening: the Russians have grown more and more concerned over the threat and are concerned over the perception of insecurity, and therefore have not wanted to allow the United States and other security services in on the ground to assist," he says.
The United States is preparing contingency plans to assist Americans in Sochi if there is an attack but, with Sochi hosting not only the Olympics but the Paralympics in March, Russia is facing a "two month endeavor fraught with real concerns," Zarate says.