KEY POINTS:
Noon and a tense stand-off at Europe's busiest station. A hundred young men in hoods and baggy trousers punching the air in rhythm confront an almost equal number of policemen.
A moment earlier the teenagers had poured off a crowded train from the suburbs - on their way, they said, to a march against education cuts in the centre of Paris. The police are sceptical and wary, the teenagers hostile. It is another day and another small skirmish in the battle for the Gare du Nord, a battle which the thousands of tourists who pour off the Eurostar every day know nothing about.
A year ago the lower levels of the station, where the urban and regional trains arrive from the suburbs and the tourists rarely venture, were filled with the smoke, teargas and chaos of a minor riot. Sparked by a heavy-handed ticket inspection, running fights between gangs and police lasted well into the night. The confrontation played a role in the victory of Nicolas Sarkozy in the presidential election and led to one of the most intensive security campaigns seen anywhere in Western Europe in recent years.
"We had lost ground. We needed to retake it, metre by metre, and that is what we are doing," said Regis Vircondelet, head of security in the northern Paris region for the Societe Nationale des Chemins de Fer (SNCF).
Certainly no one was giving ground in the face-off last week. The demonstration had nothing to do with the future of schooling and everything to do with a flexing of respective muscles. The youths surged forward, the police lines parted and the teenagers disappeared into the Metro, and the station, with nearly 600,000 travellers per day, returned to its usual routine.
This week marks a year since the new security plan for the station went into action.
"Do we have the situation totally under control? I have to be prudent," said Jean-Marc Novaro, senior commissioner of the French railway police and a key architect of the security strategy. "We have learnt a lot. But we are only just beginning."
One image recurs in the vocabulary of all who work at the Gare Du Nord: the station is "a small village", says Jean-Michel Ruscher, the station chief; it is a "town in itself", according to Ahmed Khalifa, the railway employee, who manages the homeless at the station; it is a "neighbourhood" or a "zone", according to Def, a 17-year-old from the tough suburb of Aulnay-sous-Bois, who spends his afternoons hanging around the station shopping centre.
Yet if, with its 3,000 permanent staff and massive shifting population, the station is a living, breathing society, it is one that is deeply divided.
According to Laurent Mucchielli, author and sociologist at the respected Centre for National Scientific Research, it is thus an image of contemporary Paris.
"There are two social worlds superimposed on one another," Mucchielli said. "You have the city of Paris, wealthy and powerful, next to the world that is the result of decades which have seen the poor expelled from the increasingly wealthy centre of the city towards first its edges, and then to the far suburbs. At the Gare du Nord, the two worlds meet."
They do not necessarily mix, however. The social reality is reproduced physically. The highest, best lit, cleanest and most secure part of the station is the Eurostar terminal, guarded by frontier police. Most tourists head straight from here into taxis 50 metres away or into the Metro.
Then come the platforms for the trains to Brussels or the high-speed national lines. It is only when past these that things change. Take two sets of escalators down and the only tourists here are those travelling to or from Charles de Gaulle airport. Here the platforms - especially at rush hour - are more crowded, the police much more visible, and the population much poorer and worse dressed. Whereas on the upper concourse travellers of differing ethnic origins are a minority, below they are the large majority. "Like any cosmopolitan town, the Gare du Nord has its different ethnic communities," said Khalifa, the SNCF social worker.
For Novaro, head of the railway police, the "stratification" means that "above you have a typical Paris station with relatively good security, but go down and that changes and that is where we have focused our efforts".
CHRISTOPHE D is one of the hundred or so policemen based at the station. He starts his five-hour patrol at 3pm. Usually things are calm. Christophe, who lives in the suburbs, stops fare-dodgers, inspects the documents of the homeless, directs lost voyagers, keeps an eye out for abandoned packages or teenagers on the run. He greets young men like Def easily, but without warmth.
In the grimy police station down below, under flickering fluorescent lights, a handful of down and outs are drying out.
"It's pretty quiet," he says.
This does not surprise him. There are now more resources concentrated on the Gare du Nord than on 'a small arrondissement in Paris', he explains.
They include nearly 600 cameras, two police stations and the representatives of more or less every security service that the state can deploy: from hired civilian security guards to the army.
The riots last year were both unexpected and exceptional and led to major changes, said Sebastian Jorge, security chief for the SNCF at the station.
For teenagers like Def, the changes have meant taking a lower profile.
"Some guys I know got T-shirts made with 'Gare du Nord' on the backs, because that was their gang," he said. "Now that would just lead to too much grief from the cops."
Def, who lives in a tower block in one of the suburbs with his mother and five brothers and sisters, said he came to the Gare du Nord because there were "good shops" and it was a good place to meet his friends and girls.
"They say we are gangs and criminals,' he said.
"But we don't bother anyone. Unless they bother us. And then we let them know about it."
In the French press, there has been much talk of "gangs" at the station and of hundreds of "blacks" heading for central Paris.
Sensationalism, according to Ruscher, the station chief. Instead he prefers to stress the work being done to improve lighting, signposting, information. One measure that policemen such as Novaro would like to see is a less purely commercial approach to the type of shops in the station. The groups of teenagers who cause problems - over la drague et la drogue (women and drugs) - meet at shops selling cheap clothes, trainers or mobile phones. But such businesses make a hefty profit.
Many who have studied the problems at the station echo Ruscher's charge that they have been exaggerated.
"Symbolically the image of kids from the suburbs from immigrant communities arriving in the city is very powerful," said Thomas Sauvadet, an expert in youth and crime at Paris University.
"The barbarians are no longer at the gates, they are among us. They are in the centre of Paris. In fact, they stay in places like the Gare du Nord, a long way from the wealthiest parts of the city, and pose little real threat. The response, however, is massive."
Whatever the tensions, life in the Gare du Nord continues. From the highs of the Eurostar business class lounge to the scruffiest subterranean corners of the urban RER trains, the vast majority of the hundreds of millions who pass through the station - the third busiest in the world after Tokyo and Chicago - each year get their tickets, their newspapers, their coffee and their trains without bother.
The waitresses in the Brasserie Alize who get up at 5am to cross Paris to get to work at 7am for long, badly paid days, the police, the cleaners, and station chief Ruscher pass, like any citizen in any town, uneventful days. But it is only at 1am, when the doors beneath the 19th-century facade are shut and the homeless directed outside and the cleaners come in to hose down the worn stones of the concourse and the platforms, that the Gare du Nord is genuinely calm.
- OBSERVER