MADISON, Wis. -

Every Olympic game post 9/11 has experienced concerns about terrorism. The Sochi Olympics are different. Security experts believe the chances of a terror attack during the games are at an all-time high.

“It is hard to put a number on it, how likely it is, but given the existence of organizations that would like to carry out the attack, given what we know about the imperfections of the Russian security system, I would say there is at least a 20 to 30 percent chance there will be an attack,” said Andrew Kydd, a professor at the University of Wisconsin-Madison, an expert in terrorism.

Sochi’s close proximity to where Russia has been fighting a bitter and bloody war with rebels from Chechnya raise the possibility of a terror strike.

“There’s a lot of reason to think that there’s a heightened risk of terrorism in this particular Olympics. I mean, it is like having the Olympics back in Northern Ireland in the 70s,” Kydd said.

Terrorists have also demonstrated in recent months the ability to carry out bombings of transportation hubs in areas near Sochi. Kydd believes those transportation centers will be vulnerable targets during the games.

“All of those cities in the region are all going to be full of people transiting in the train stations, in the airports and all those areas will be targeted,” Kydd said.

The threat has resulted in some family members of Olympians deciding to stay home.

“Well we decided not to, I mean part of it is obviously the security,” said Bob Suter, a former Olympian and the father of Ryan Suter, a defenseman for the U.S. Olympic hockey team.

Bob Suter said security concerns are not the only reason his family will stay home for these Olympic Games, but staying home will allow Ryan to focus on the games and not worry about his family and security concerns.

“It seems like every year, every Olympics, it gets to be more and more talk, and worry about security and stuff than there is about the games themselves,” Bob Suter said. “But in the world we live in now, security and there are so many problems that we’ve got to deal with.”