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PARIS - Ever since the 9/11 attacks of 2001, France has sensed the threat of terrorism to come from Islamists.
But, if the authorities are right, a co-ordinated spate of attacks on the high-speed train system could signify an unexpected return by France's violent ultra-left, which fired its last shots more than two decades ago.
Five young people have been placed in custody by anti-terrorism police on suspicion of sabotaging the Train a Grande Vitesse (TGV) network. Four others are being probed for suspected involvement with "a terrorist organisation".
In a well-planned assault, specially designed steel bars were looped around the overhead electrical cables from which the TGV locomotives draw their power. The bars were designed to lock tight against the cable if they were pushed forward.
In the early hours of November 8, four trains fell into the trap as they raced along the TGV system.
Their overhead connectors, called catenaries, pushed against the bars, which then locked tight - and as a result each train ripped down kilometres of cable before finally coming to a halt.
There were no casualties or derailments, but 160 trains were delayed and the state-run SNCF rail company is facing a huge repair bill. A similar attack occurred on October 26 on an eastern branch of the TGV network.
The finger of blame initially pointed at disaffected railway workers, angry at reform of the SNCF.
But, in a scenario that could have been written in the 1980s, a swoop by 150 police in four cities laid bare what the authorities call an "invisible cell", run by a highly educated revolutionary from a safe house in rural France.
The group "is similar to a terrorist enterprise ... [whose goal] is to target the apparatus of state through violence", said Paris prosecutor Jean-Claude Marin.
The alleged mastermind is Julien Coupat, 34, who grew up in a mansion in a park at Malmaison, in the Paris suburbs.
Coupat, the son of a doctor and a top woman executive in the Sanofi-Aventis pharmaceutical giant, studied sociology at Essec, one of France's top business schools.
Revolting against his privileged roots, he set up an underground organisation and authored a small book, l'Insurrection Qui Vient (The Coming Insurrection), published by a small firm and promulgated on the internet, with tips on the armed struggle, according to Marin.
Under Coupat's inspiration, a group of four women and two men, mostly in their early 20s, set up an alternative-lifestyle commune in a farmhouse in the village of Tarnac, in the rural department of Correze, southwestern France, say Marin's team.
Police say they began monitoring Coupat and his partner, Yldune L., on a tip from the FBI, who reported seeing the pair at a demonstration in New York outside a United States Army recruiting office. In the farmhouse, according to press reports, police found bullet-proof jackets, ladders, train timetables, instructions on how to make petrol bombs and blacksmith's grips, as well as tracts calling on support for a demonstration in Vichy on the sidelines of a European Union meeting. In a Paris flat, investigators found metal tubes 2.2m long.
Defenders say the nine are simply political dissidents. They accuse the authorities of hype and say the evidence is circumstantial.
"There's no relation between the accusations, which are baseless and in any case relate to damage that was no threat to life, and a terrorism case," said Coupat's lawyer, Irene Terrel.
The alleged cell seems almost like a time warp from the "years of lead", when France - like Germany, Italy and Belgium - was rocked by far-left terrorists.
In those days, most guerrillas were 1968-ers who became convinced that transformation could come only through bullets and bombs, not through political activism.
The principal group, Action Directe, carried out 17 attacks between 1979 and 1986, focusing on symbols of the state, corporate chiefs and the US military. Twelve people were killed, including the head of Renault, Georges Besse, while a former minister of justice, Alain Peyrefitte, narrowly escaped with his life.
Interior Minister Michele Alliot-Marie said last week she had always been concerned about a resurgence by the violent fringe, which in the past happened when mainstream parties were weak.
Analysts agree fringe radical groups are being offered a recruiting opportunity by the global financial crisis, which sows doubt in capitalism, by divisions in the Socialist Party and by the decline of the once-mighty Communist Party.
But they also say the "anarcho-autonomous" movement of today bears little similarity to that of the 1980s.
It is more amorphous, has no doctrine other than a hatred of capitalism and is likely to have been influenced by environmentalism. And, at the moment, at least, it is far less disposed towards violence, especially against people.
ECHOES OF ACTIVISM
* French police say a tip from the FBI led them to monitor the suspected mastermind of a group alleged to have sabotaged the French rail network.
* The son of a doctor and a top woman executive in the Sanofi-Aventis pharmaceutical giant, Julien Coupat is the author of a small book, l'Insurrection Qui Vient (The Coming Insurrection).
* Having studied at one of France's top business schools, he is believed to have then revolted against his privileged roots, set up an underground organisation and started an alternative-lifestyle commune in rural southwestern France.
* Analysts believe his group is part of a resurgence of a fringe radical movement that swept through France and Germany in the '70s and '80s.
