'If you wanted to light the fuse of a race war in France, this city would be a clever choice'
The Euro 2016 football championship had passed off without terrorist attack. President Francois Hollande had announced that the state of emergency, declared after the November 13 attacks in Paris, would lapse at the end of this month. The summer holidays were starting. The economy was beginning to revive.
And now this. The truck attack on Bastille Day on crowds watching fireworks at the Nice seafront has all the fingermarks of devilish timing and planning by Isis.
The attack happened on a day which celebrates the French, and Western, values of democracy and fraternity. It targeted families, including children and babies, at a moment of joy and relaxation. It targeted a city which symbolises France as the world's most popular tourist destination and a beacon of joie de vivre.
There is something doubly and trebly terrifying about the use of a banal 20-tonne delivery truck to deliver 84 brutal, callous and pointless deaths. Guns and explosives the security services can seek to monitor and control. But how can anyone stop a truck from driving into a crowd?
It may well turn out that the perpetrator of Thursday's outrage was a "lone wolf" - not directly controlled by Isis. That would also be doubly and trebly scary.
Isis may not pull all the strings, but its strategy and propaganda have implored sympathisers to find their own methods and opportunities to kill the "filthy French and Americans" and other "miscreants".
The November 13 attacks in Paris were, in a sense, misleading. They needed considerable logistics and planning.
The real war now facing the West - not just France - has been openly boasted of by Isis leaders. It involves random and scarcely planned attacks on Europe as the "soft belly" of the West by individuals inspired, but only loosely guided, by the jihadist gospel of hatred and revenge.
The aim has also been clearly stated: to provoke a white backlash against the Muslim populations of Europe, starting with the 4.7 million Muslims in France. This will in turn, Isis believes, recruit many more young Muslims to its cause.
In the wake of the Charlie Hebdo attacks in February last year, the Bataclan and other Paris attacks in November and the Brussels attacks in March, this strategy failed.
It is to the credit of the vast majority of ordinary French and Belgian citizens that there has been no significant anti-Muslim backlash. It is to the credit of the vast majority of the Muslim populations in Europe that they have rejected the warped logic of Isis.
But how long can we expect people to react with such common sense? The choice of Nice as a target - whether deliberately calculated by Isis, or not - is potentially explosive. Paris and Brussels are cosmopolitan, Leftish-leaning, open-minded cities. Nice is by far the most Right-wing of the large towns and cities in France, a bastion of the hardest-edged version of Nicolas Sarkozy's centre-Right and also of the far-Right Front National.
A large part of its white population is descended from the "pied noirs" - French colonists, who were forced out of Algeria in the early-1960s.
Nice also has a large Muslim population. They live within the city boundaries, not locked away in the poor multi-racial suburbs, like in Paris, or Lyon.
If you wanted to light the fuse of race war in France, Nice would be a clever choice.