By Gabriel Stargardter
PARIS (Reuters) -Around 50 khaki-clad men riding atop a black armoured truck approached an abandoned office building on the outskirts of Paris one spring morning and blew open a second-storey window with an explosive device.
After clearing shards of glass from the window frame, they shuffled through the gaping hole and into the graffiti-covered building in search of hostages - in reality junior members of the Gendarmerie - held inside.
The training exercise, held in preparation for the July 26-Aug. 11 Olympic Games, was one of the final dress rehearsals for an event nobody wants to happen.
Founded 50 years ago after the 1972 Munich Olympics massacre, in which 11 Israelis died in an attack by a Palestinian militant group, the GIGN is one of France's elite tactical units, responsible for freeing hostages, counter-terrorism operations and other high-stake raids.
Should such an incident occur at the Games, which took a step closer to reality on Wednesday evening when the Olympic torch arrived in Marseille, the GIGN will be summoned.
Ghislain Rety, commander of the GIGN, said his team was ready.
"It would be dishonest to say there is no risk, but it is minimized as much as possible," he said.
Rety acknowledged a certain symmetry between the GIGN's origin story and its Olympic mission but hoped the force can celebrate its anniversary without being called into action.
Paris has been on high alert since 2015 Islamist attacks that killed 130 people and injured hundreds more. Still, the Olympics, and particularly the Opening Ceremony, represent a security challenge like no other.
With 300,000 people watching from the river banks and millions more tuning in on TV, the ceremony is due to take place on barges along a 6-kilometer stretch of the Seine.
Wars in Ukraine and Gaza have complicated security planning, and French President Emmanuel Macron has floated potentially scrapping the river ceremony and reverting to back-up plans.
Rety said the GIGN would place two men - in plain clothes, so as not to distress spectators - on each of the barges carrying athletes, with 350 GIGN officers assigned to the Opening Ceremony.
Sharpshooters will be installed on the roofs of the grand buildings that line the Seine, with forces also deployed below the city streets. In all, around 50,000 French police and soldiers will secure Paris during the Games, with additional help from a few thousand foreign security officials.
The GIGN, which typically undertakes eight operations a day across France and the rest of the world, has been preparing for the Olympics for around 18 months, Rety said. One of the main difficulties had been coordination with other French forces and with foreign delegations.
"But we like complication," he said. "It's a nice challenge."
As the training exercise wound up, a camouflaged chopper landed on top of the building and picked up the GIGN officers, who attached themselves to a rope. It then took off, dangling the men over the suburbs of Paris before they were deposited, one by one, back in the office car park.
(Reporting by Gabriel Stargardter, editing by Ed Osmond)
