Olympics Countdown: Clear and present danger

Athletes at this summer's Olympic Games in London will compete in a number of sports, including shooting, fencing, archery, boxing, wrestling and the martial arts.

While the pain and struggle of intensive training and rivalry could be rewarded by Olympic glory, no young athlete's life will be on the line.

Yet physical danger still remains. Why else would London be ringed by anti-aircraft missile defences, with more than 10 000 British soldiers deployed, and all 4000 MI5 staff focused on the city's safety?

Communication intercepts have already forewarned of terrorists plotting to attack the London Olympics, the ultimate international terrorist target. Terrorists crave the publicity of a well-orchestrated attack, and worldwide media will be focused on the Olympic Games.

To carry out such acts, terrorists need a local support base, and London is a diverse city and home to political dissidents of all persuasions. These attacks have maximum impact in crowded areas, and the streets of London will be swarming all summer with the hustle and bustle of the Games.

Meanwhile, 2012 commemorates the 40th anniversary of the 1972 Munich Olympics, unfortunately remembered most for the kidnapping and massacre of the Israeli team at the hands of the Palestinian militant group Black September. Terrorists seem to exhibit a dark fascination with relevant anniversaries.

Military security in London will be much stronger than in Munich, which makes the repeat of a similar attack much less likely.

However, those complacent about terrorist ties with the Olympics should remember July 2005. Shortly after the city was awarded the 2012 Summer Olympics, the celebration was marred the following morning by four synchronised terrorist bombings on the London transport network.

Of all the international visitors descending on London this summer, one would be distinctly unwelcome: a lone wolf terrorist aiming to spoil the celebration by committing a solo act of political violence at one of the Olympics sites, or in another crowded London location.

There is an Olympic precedent for such an individual crime. An American lone wolf, Eric Robert Rudolph, blighted the 1996 Atlanta Summer Games by planting a 40lb pipe bomb at the Centennial Olympic Park, which resulted in the deaths of two people and injuries to more than 100 others.

Rudolph's profile is disturbingly reminiscent of Anders Breivik, the Norwegian Islamophobe, who killed more than 70 of his compatriots in July 2011, almost a year prior to the opening of the London Olympics.

In the wake of his attacks, and his expository manifesto, written in English and datelined London 2011, counter-terrorism services across Europe have intensified the hunt for roaming lone wolves.

With a minimal social network of plotters, RMS estimates that the chance of interdicting a lone wolf plot may only be one in four.

With more than one terrorist involved, communications between conspirators can betray details of an emerging plot. But who knows what is in the mind of a lone wolf, such as Mohamed Merah, who terrorised the French city of Toulouse in March 2012?

The capability of individual reckless action to disrupt a London sports event was brought home in April when the university boat race was halted by a protest swimmer, Trenton Oldfield.

He was politically motivated and, like a Jihadi, could easily have lost his life for his fervent beliefs, if struck in the head by a racing oar. Alarmed by this act of surprising audacity, officials are stepping up security around open Olympic events, such as cycling, the marathon and the triathlon.

Game theorists remind the public of the principle of terrorist target substitution: given targets of similar value, the target with the worst security will tend to be attacked. London is a vast metropolis. Key parts of the city will be heavily protected this summer; most of London will not.

It was thus during the height of the Irish Republican Army campaign during the 1980s and 1990s, when bridges, stores and commercial offices were targeted.

The IRA had mastery in the terrorist art of striking weak targets of opportunity. Terrorists are keen students of history, and will have learned from the experience of past attacks on Britain's political, economic and tourist capital.

Dr Gordon Woo, catastrophist, Risk Management Solutions