Nice: The sun shone brightly on the Nice Promenade des Anglais today. It was hard to imagine that a horrible slaughter had happened there just a few hours before. A light breeze ruffled the white peaks on the waves as they gently splashed the golden shoreline with its famous hotels, shops and casinos .

But all was quiet on the beaches of Nice and the whole of France was in mourning. The day before, a lone truck driver, a Tunisian immigrant, had mowed into a crowd of innocent onlookers at a fireworks display on the Promenade des Anglais.

At the time of writing the death toll stands at 84, of which 10 are children, but more than 50 others are in critical condition in hospital, including one Irish person.

There are foreign tourists and Muslims and parents and sons and daughters who will forever be part of this terrible moment in French history. Charlie Hebdo, Bataclan, now Promenade des Anglais, three places forever frozen in horrific memories as the merciless killers did their dirty work.

It is the mindset of the Jihadists that is the most threatening to the safety and wellbeing of society. On the morning of the attack I happened to pass near the street in Nice where the monster who killed everyone was still living and probably plotting.

It is a miserable enough downtrodden area near the main train station, mainly inhabited by immigrants. But in all the time that I have traversed there over the years, I have never felt threatened as I would in a similar Banlieue in Paris. Mainly the Arab shopkeepers that that I have met there have been civil and welcoming.

The slaughter struck at the heart of a French cultural celebration as thousands watched the fireworks display in the Bay of Nice. It was the night of July 14th, the day when the French celebrate the storming of the Bastille and the beginning of the French Revolution in 1789.

The French Revolution gave the world the immortal motto ‘Liberté, égalité, fraternité’ (or ‘liberty, equality, fraternity’). Nowadays the news from France is less propitious.The Nice atrocity follows the recent terrorist outrages at the Bataclan and the Charlie Hebdo massacre, among others. It is hard not to conclude that these acts are a sustained and murderous attack on the western values of liberty and democracy espoused in the French revolution.

After the success of a mainly incident free European soccer championship in France, the French had dared to breathe and the government had planned to allow the state of emergency to lapse. This has all changed. President Francois Hollande has now extended the state of emergency and there has been an immediate mobilization of 10,000 additional soldiers and the call up of reservists to guard the borders.

Here's how you can help the victims and survivors of the Nice attack https://t.co/fzgIK7SQkQ pic.twitter.com/28rHWuD7WV

— Mashable (@mashable) July 15, 2016

It is hard also not to feel these Presidential pronouncements are meaningless gestures as many people believe the enemy is not outside the country but resides within the seething walls of the deprived suburbs of Paris and the cities of the South.

When I passed along the Promenade des Anglais on Wednesday evening last, a day before this atrocity, I could not fail to experience once again the sheer exhilarating spirit of summer in Nice, as young and old delighted in a carefree holiday atmosphere. The celebrated promenade,over five miles long oversees a crowded beach and blue sea below. It is the spine of Nice and a magnet for strollers, joggers and cyclists. Perhaps some of the people I saw, including the children, were killed. I will never know.

Events in France such as the fireworks celebration of July 14th, are community occasions. There is a shared delight in the spectacle and normally no public drunkenness or hooliganism , Whole generations of families will attend and enjoy the event peacefully together. The van killer knew that.

The obscenity of this slaughter will be all the more bitter to comprehend as a result and the grief will be all the more heart breaking when the personal details and photographs of the dead are published in the coming days .

So a kind of monster has risen up to snatch the life away from these innocents. One report describes the terrorist as a having a demented laughing appearance as he ploughed into the crowd. A harrowing amateur video shows a heroic motorcyclist trying to open the door of the truck as it moved along the promenade only to be swept underneath the wheels .

Many questions will be asked about the lax security that allowed this large truck to pass down a crowded promenade. There were no police anywhere to be seen in the videos taken during the massacre and immediately afterwards.

Questions too are being asked about the leadership shown by President Hollande. He hardly cuts an authoritative figure these days. Plagued by images of him riding incognito on the back of a motorcycle as he escapes from the Elysee Palace for a romantic rendezvous or attempting to justify the 10,000 euros a month for a haircut that is paid to the coiffeur of his diminishing curls , he is facing reelection next year and the far right may well be gaining fast.

But there is a perception that Nice, and especially a suburb to the north of the city, is a hotbed of Islamic extremism along with other cities in the south such as Montpellier and Marseille (where the Muslim population is reportedly 40 per cent).

But blanketing a whole race or ethnic group with the same extremist label is morally and practically indefensible. It was this same intolerant attitude that soured the lives of generations of Irish in England throughout the troubles.

The fact is that these extremists are often second generation sons of immigrants who came to France and accepted that they needed to work hard to establish themselves in their adopted country. Their recalcitrant sons however grow up physically and culturally isolated from more wealthy, integrated neighborhoods and then become fodder for ISIS.

That is not to excuse their extremism but the fact remains that the official French policy of assimilation of all citizens regardless of creed or background rather than recognizing that France is a multi-cultural society has not worked. Many feel left out and feel they have no future or allegiance to France

The question always seems to return nowadays to this issue of immigration. Many think that it was the main catalyst for the Brexit vote in UK. Similarly in France, it s is likely to dominate the Presidential election next year.

My acquaintance Michel from Nice, who always struck me as being a fairly unprejudiced fellow, surprised me last week when I asked him if he was going to watch France playing in the final of the European championship. No, he said. I support Nice football team, not France. My own father was an immigrant from Russia, he said, but nowadays there are too many immigrants on the French team. It does not represent the true France.

There is a lot of work left to do to bring this continuing nightmare to an end.

Donal O’Dowd is an electrical engineer working in France for many years. He has vacationed every year in Nice.

Related: Crime