Donal O’Dowd is an Irish-born engineer, writer and resident of Paris.

The shocking terrorism in Paris on Wednesday, which resulted in the cold blooded execution of twelve citizens, journalists and policemen, is a savage attack on western civilization and its values. It is France’s 9/11.

It strikes at the heart of our comprehension of where religious extremism will go next. It is up there, in its evil and inhumanity with the recorded beheadings by ISIL of the western captives in Iraq.

That it should happen in France, though, is no surprise. The country is long struggling with a severe crisis of segregation where a huge immigrant population lives in the poorer ‘banlieu’ or ghettoized suburbs of the major cities while the center is held by the white and the tourists.

Think of Paris and a foreigner might only see dreamy boat rides down the Seine, romantic walks under the leafy green trees of the Champs de Mars in the shadow of the Eiffel Tower or a sunny afternoon watching the little ducks in the pond at Jardin de Luxembourg.

A tourist never really never sees the monotonous drudgery of life in the dreary tower blocks outside the peripherique of Paris, the police no-go areas where there is a constant struggle against the crime and drug addiction.

This is where most of the immigrants live, mostly in a struggle to achieve a decent respectability in their lives but often the without the sincere help of the state that started the mess in the first place.

When France lost its empires in the East and Africa and relinquished its prized possession of Algeria, it reluctantly opened up its borders to a mass wave of immigration from the then third world. Almost 20 percent (or 12 million people) of the population of metropolitan France was immigrant in 2008 and the number has risen inexorably.

Very few of those have made it to the top. Few are in government or in the civil service. The squeaky clean foyers of the magnificent office blocks in Las Defense are not crowded with workers of African or Algerian origin.

It is as if the French settled majority wants to forget about the strange horde of travelers at their door and consigned them to live in the ‘sticks.’ France does not tolerate discrimination, officially. It preaches toleration and equality and exhorts a unity of citizens. But that doesn’t work in practice.

An Algerian colleague of mine told me about the subtle small–minded discrimination that began when he was growing up in northern France. Opportunities for advancement were limited. Job offers were non-existent for him when he graduated, unlike for his non-immigrant colleagues.

He could have accepted that, like some of his friends, and led a life of idleness or crime, but he decided to fight it. But the struggle continues today. He has trouble renting an apartment and notices the change in attitude of the landlord when he speaks his name to the landlord.

A French teacher friend of mine says the immigrant banlieus of Paris are dens of insurrection. His pupils tell him that they are really not French and they will not speak French but Arabic. They have no loyalties to the state in which they live. Even at school going age, they have already given up on their futures in the society of which they are citizens. They congregate in gangs in the Metro stations and shopping centers of central Paris at weekends.

At Chatalet station I have often seen them being harassed and intimidated by the police. I have seen also the results of the petty crimes that they visit on the city. Official France might sometimes wish them go away but the reality is different.

In this cauldron of resentment, extremism will flourish. I was no surprise really to me when I heard that some Islamist social media postings were reveling in the atrocious happenings at the office of Charlie Hebdo. Here was the comeuppance for the smug satirists of their core values. It is a sick mentality that devalues and debases human life in such a way.

But France itself is a conundrum of contradictions that has not tackled its crisis of immigration. There is fear everywhere. That is why The National Front of Le Pen is thriving. It may be a long time yet before the principles of the revolution, of liberté, égalité, and fraternité are felt again in Paris.

Read more: Dublin holds #JeSuisCharlie vigil in solidarity after Charlie Hebdo massacre (PHOTOS)

Just one of the #JeSuisCharlie vigils held around the world in solidarity and revulsion at the Charlie Hebdo attack.Getty