By David Fuller
BBC News Online
Lynn Davies won a gold medal in 1964
The Olympic Games are a prime target for terrorists - with the world's media focused on the competition, they know they would be guaranteed the oxygen of publicity.
The way the Palestinian/Israeli conflict swept to the world's attention after 17 people died in the Munich massacre of 1972 shows how effective an attack on the world's top sporting event can be.
It never used to be this way, and many traditionalists mourn the loss of innocence, the days when a visit to the Olympics would allow people to meet and mingle with their heroes.
Former UK long jumper and gold medallist at the 1964 games, Lynn Davies, says the very nature of the Olympics has changed in his lifetime.
'Lynn the Leap' as he was dubbed by an admiring Welsh public, first competed in Tokyo in 1964, and then in Mexico City in 1968, Munich 1972 and Montreal in 1976.
"In 1964 it was a different age, terrorism hadn't entered the vocabulary at all then," he said.
"We came and went as we pleased, I can't even remember having to show security passes to get in and out of the Olympic village - there was a very relaxed approach."
The security was equally relaxed in Munich eight years later, when guards spotted men climbing into the village wearing tracksuits and carrying bags they assumed it was just athletes returning from a late night.
The kidnap and subsequent deaths of 11 Israeli athletes was to transform the games completely.
"In Montreal in '76 you could really see the difference," Mr Davies said. "They spent fortunes on security and it became quite obtrusive.
"I remember 100 athletes queuing to get into events - we were very conscious of the security - it felt like a turning point."
The 1972 terrorist raid changed the games forever
Since then more and more money has been spent on security for the games, culminating in the massive operation planned for Athens which will see 50,000 police and troops deployed.
Organisers have pledged to spend three times as much on security as was spent on Sydney 2000.
As ex-champion swimmer Mark Spitz's comments have shown - he raised the possibility of a US pull-out - this is still not good enough for some.
A recent poll in America found 52% of people believe an attack on the games is likely.
Mr Davies, who is due to travel to Athens as President of UK Athletics, said he was confident everything was being done to ensure the 2004 games went ahead safely.
"Everyone involved is concerned about the possibility of terrorism, but we are sure the Greek authorities are doing everything in their power to ensure safety."