Through his bathroom window, Dick Quax was an eyewitness to the bloodiest moment in Olympic history. Like the rest of the New Zealand team at the 1972 Munich Olympics, the champion runner was next door when terrorist group Black September stormed the Israeli compound.

The New Zealanders were trapped inside the cordon as security forces worked desperately to free the Jewish hostages just metres away.

"From our bathroom window, we could quite clearly see what was going on inside the Israeli building," Quax recalled this week.

"We could see the masked heads [of the terrorists], we could see food being brought in, and we watched German special agents crawling around in their tracksuits. It's as close as I ever want to get to anything like that."

Quax, who went on to win an Olympic silver medal in the 5000m four years later, had been within earshot of an attack as unexpected as the September 11 assault on New York.

When the siege was over, 11 members of the Israeli team, five terrorists and one policeman were dead, and the Olympic movement was traumatised.

As preparations for this year's Athens Games heat up, those horrific events in Munich serve as a warning bell. New Zealanders might not be a prime target but all competitors and spectators face risks in attending the XXVIII Olympiad.

The Greek security forces are going to incredible lengths to build a shield around the 16,000 athletes and officials who will descend on the city in less than two months' time. Spy planes, Nato ships, radiation detectors on the hunt for dirty bombs in suitcases, and tens of thousands of armed soldiers and police are among the amazing armoury at the disposal of Olympic security commanders.

But will these intense manoeuvres be enough to prevent something as low-key yet lethal as a lone militant with a bomb in his backpack taking a train ride? It is a question worth asking, particularly in Greece, whose recent history is littered with the carnage inflicted by local paramilitary groups.

On the other hand, will the security effort at these Olympics destroy the spirit of the event, turning them into the Rambo Games?

Arriving at the new Eleftherios Venizelos Airport after the arduous flight from New Zealand is a surprisingly smooth experience. We expected a city under siege, but there are no arrival cards to fill out at passport control and few overt signs of beefed-up security.

The handful of customs officers on guard smiled as photographer Mark Mitchell and I sauntered past without interruption once we had collected our bags.

A few days later, a senior official from the Ministry of Public Order explains this is all part of the plan. An arrival card was not necessary, he says - all passengers' names and details are screened and checked against European intelligence databases even before their flight touches down.

Colonel Eleftherios Ikonomou, spokesman for the ministry, says these are the kind of steps Greece is taking to find the balance between tight security and a welcoming environment.

"We are trying to preserve the atmosphere of celebration of the Games," he says.

The scale of the exercise is daunting and impressive. Greece will spend €1 billion ($1.94 billion ) on security, more than four times what was shelled out at Sydney and roughly as much as has been spent at all previous Olympics put together.

The Greek Police, Army, Air Force and Navy will be on duty, Nato's Awacs spy planes will cruise above the country and its ships will watch over the high seas. A strict no-fly zone will be enforced above the Olympic venues. Any plane ignoring instructions and which seems intent on a September 11-style attack will be shot down.

Athletes will be guarded around the clock, even away from the venues.

It is an operation unparalleled in history, although the threat of attack is hardly a new phenomenon for the Games. Even in ancient times, the Olympics were a juicy target for those intent on violence.

Dr David Gilman Romano, senior research scientist at the University of Pennsylvania Museum of Archaeology and Anthropology and an expert on the ancient games, says there were serious violations of the Olympic truce.

"On more than one occasion Greek hoplite soldiers stormed the Sanctuary of Zeus at Olympia," he says. "In one instance, they interrupted the pentathlon event of the Olympic Games. Wars were fought between rival Greek city-states over the control of the sanctuary."

In the modern era, Munich shook the world. Quax remembers how easy it was to move around the Games' complex.

If you wanted to get a friend or family member into the village, no problem - you'd just borrow an accreditation pass off a fellow team-mate. Sure, there were photos on the passes, but security guards never bothered looking, recalls Quax.

Black September changed that. In the build-up to all subsequent Games, security has been a major issue.

Before the Seoul Games in 1988, the world fretted about the threat from North Korea or paramilitary terror groups sponsored by the communist state. A Newsweek story published in the New Zealand Herald just weeks before the Games posed the question: "Would the Olympics be safer in Libya?"

If Black September made security issues a major concern for Games' organisers, the September 11 attackers have pushed it to No 1 on their agendas. Athens will be the first summer Games since al Qaeda's 2001 strike on America.

Sitting in an office next to what will become a nerve centre for security operations, Ikonomou admits that Greece had to recast its plans after the Twin Towers hijacking and the sequence of terror attacks which have unfolded since, from Russia to Saudi Arabia, Turkey, Spain, and Indonesia.

"The Olympic security budget was increased and there was a new basis for the planning," says Ikonomou. "We have multi-level threats and this has forced us to change the whole scenario."

Last week, Athens was in a peaceful mood. It felt safe to walk around. The most visible sign of security was at the British Embassy, where police armed with automatic weapons kept watch from behind concrete barricades positioned to thwart suicide car bombers.

Elsewhere, squads of police were sometimes clustered near major buildings or sites, but the mood was relaxed. Two officers, the only women police officers on motorbikes in Athens, were even prepared to pose for a photograph.

Come Games time, things will be more muscular. Entering Olympic venues will be tougher than boarding an international flight and the athletes' village is intended to be one of the most secure sites on earth.

Those wanting to enter most sites will have to pass through two security checks, with strict enforcement of the accreditation procedures and screening for everything from drugs to guns to dirty bombs.

"We have to be 100 per cent sure that whatever enters a venue, either people or objects, is totally controlled and screened," says Ikonomou.

Another key part of the operation is intelligence-sharing arrangements. Greece has smoothed the way for close liaison with its Balkan neighbours and Turkey, no mean diplomatic feat given their history, and is working closely with its European and Nato allies.

A key decision was to set up an advisory task force comprising Australia, France, Germany, Israel, Spain, Britain and the United States. Through this body, these countries have been brought into the security loop. Not only does Greece benefit from the value of their advice, but it may also serve as some sort of insurance against these Governments speaking out about perceived failings.

Those who have studied the Olympic security planning arrangements are impressed. Dionyssis Gangas, head of the Athens 2004 organising committee's international relations division, admits it is hard to stop "madness".

"In this world, one can never say never." But he believes all measures possible have been taken.

Dave Currie, the New Zealand team chef de mission, is more than happy to leave security in the hands of the Greek forces. "I would rather be in Athens at the Games than anywhere else," says Currie. "The chances of something happening with that level of security are [slim]."

Jeff Bukantz, captain of the US fencing team who has been to most Games since 1968, went on a fact-finding mission to Athens to assure himself and his team members about their safety. He was particularly interested in four areas of potential concern - the village, the venues, transportation and public zones.

On the first two counts, he was satisfied by what he saw. For transportation, he is happy, except about the possibilities of traffic jams. "That could put a bus at risk."

As for the public areas, he has resigned himself and the team to the fact that they will not be able to mooch around as tourists. "We're going to practise, compete, see other events and spend plenty of time in the village," says Bukantz. "But we're not going to Athens to sightsee and worry about eating dinners in town at night. We'll try to stay where we are safest."

A former US State Department adviser on terrorism, Professor Henri Barkey, of the Lehigh University, says there is no doubt the Greeks have spent enormous amounts of money. "But no system is foolproof and theirs won't be either," says Barkey.

"In Greece, the problem is that there is a history of Middle Eastern terrorist groups using the country as a transit point in the 1980s. What I do not know is how much of that infrastructure is still available. That said, the Olympics is the biggest target in the near future and I would be surprised if not most of the al Qaeda-affiliated groups are looking at ways to do something spectacular."

But in Greece there are not only international terror networks to consider. Around central Athens, it is not unusual to find graphic anti-American graffiti expressing a sentiment not far from the surface in Greece, where some are still resentful about US involvement in the military take-over in 1967.

All over Europe the unpopularity of the war in Iraq means anti-American slogans are familiar. But they take on a more sinister tone in a capital where local guerrillas have a dangerous past. The most deadly group, dubbed November 17, was shut down two years ago with the arrest of its key members, but that came after a 27-year reign of terror during which more than 20 people were killed.

In the past few months, other groups have been flexing their muscles, albeit on a small scale. Three blasts outside a central police station were claimed as the work of a little-known radical group called "Revolutionary Struggle".

The anarchist group published a statement in a local weekly newspaper declaring that the country had been turned into a fortress, showing the Games were about war, not celebration.

"All members representing the international capital, global mercenary killers and state officials, as well as well-off Western Olympic tourists planning to be here, are not welcome," said the statement.

Barkey thinks these local militia are more likely to be active. "The Greeks will be able to control most of them, but my guess is there will be some incidents just like the ones we saw with the anarchists."

Alexander Kitroeff, author of the book, Wrestling with the Ancients: Modern Greek Identity and the Olympics, thinks the string of incidents may be a blessing in disguise, serving as a reminder about the threat of the anti-establishment, anarchistic minority.

"There are no public statements about moves to suppress those groups, although we can assume the authorities are tracking them closely," he says.

Ikonomou dismisses the incidents as low-key but says all threats are taken seriously. "We face all isolated incidents in a professional manner. The Hellenic police have great experience in all these matters."

It is also a fact that Greece, despite international reports to the contrary, is determined that its forces alone should be left to handle the security of the 202 Games teams. Ikonomou says there have been no official approaches from any team about making their own security arrangements and, in the event, such requests would be rejected.

"It's not a question of national pride or sovereignty. It's a practical matter. Imagine what would happen if 202 delegations brought their own security forces?"

The Greeks are offering extra security to teams where it is considered there is a medium or high-level threat. Diplomacy means he will not name names, but it is likely the list includes America, Israel, Britain and Australia.

Their athletes are to be tailed around the clock by armed guards, even on sorties away from the village to experience local flavour and cuisine.

The risk is that the environment created by what will be the most wide-scale security operation outside a war zone will detract from the sense of celebration.

In many ways, the biggest challenge for Olympic security organisers may not be keeping terrorists at bay, but ensuring that the setting does not detract from the spirit of the Games.

It is something of which the Greeks are well aware. The president of Athens 2004, Gianna Angelopoulos-Daskalaki, told a conference on security last month: "We want our athletes to have only one concern this summer - delivering an Olympian performance as the world looks on."

Put freedom on winner's dais

AS some high-profile athletes contemplate pulling out of the Games this year because of fear of an attack, Greeks are calling for the world to make a stand against militants by turning up in Athens in August.

Public statements from athletes, including tennis player Lindsay Davenport and several NBA basketballers, have shaken the United States team, in particular. Former champion swimmer Mark Spitz even floated the idea that the US team could pull out altogether.

Faced with the prospect of a boycott of sorts by stealth, Games organisers and the Greek Government want these Olympics to become a turning point.

The deputy Minister of Culture, Petros Tatoulis, told the Weekend Herald that the first Olympics since September 11 presented the world with a magnificent opportunity.

"As people of this planet, we can decide," said Tatoulis. "Either we can live in phobia and fear of the unknown and threats of terrorism or we can approach life with a new optimism.

"Athens 2004 has a belief that people can insist on a better life. That is the main motto. We believe better days will come and that is the new spirit the Olympic Games will contribute."

Eleftherios Ikonomou, spokesman for the Ministry of Public Order, said it was important to remember one of the founding ideals of the Olympics was the bringing together of people of different civilisations.

"We can beat terrorism through this celebration," he said. "Always by taking security measures, but we can win over terrorism."

He said the defence of freedom was particularly important for athletes from New Zealand, so many of whose soldiers had given their lives fighting in Greece during World War II.

"New Zealand's presence here is going to be in honour of those people who struggled for freedom. This is going to be the best answer to the new environment that we have these days."