Algeria's terror connection
It followed a spate of explosions in Paris in the 1980s and 1990s, and a foiled Algerian suicide plot to fly a plane into the Eiffel Tower.
Former chief prosecutor in the French anti-terrorist courts, Ms Irene Stoller, told the BBC's File on 4 radio programme that for too long the authorities in London refused to act because they did not feel directly threatened.
"It was a case of 'It's happening to my neighbour, not to me, so it's not my problem,'" she said.
"We know that they leave France, go to London where they are given new passports and identities, and then go to the training camps where they learn to plant bombs."
Back in the UK, the Algerian Refugee Council chairman, Dr Mohammed Sekkoum, says a substantial number of active "terrorists" have slipped into the country with their families, seeking asylum.
A running sore in Anglo-French relations is the UK's refusal to extradite an Algerian accused in connection with the 1995 attack in the Paris Metro.
In the months after the bombing, Rachid Ramda was arrested in London.
The French wanted to put him on trial but when the UK Home Secretary David Blunkett finally gave the order for his extradition it was blocked in the High Court.
History will regard the Neville Chamberlains of the World with the derision they so richly deserve.