This article first appeared in Le Monde.

PARIS - This time, it's Brussels, the heart of Europe, that was hit by Islamist terrorists. They targeted this free city, where humor, impertinence, a Belgian way of not taking yourself too seriously, is the opposite of what these barbarians have in mind: cheap certainties, hatred towards others, the violence of the "pure." The deadly jumble of ideas driving these European-born jihadists is the polar opposite of what cosmopolitan Brussels, the capital city of a European project that was their symbolic target, stands for.

Every time it occurs, this not-so-blind violence takes us by surprise. It shouldn't. After Madrid, after London, after Paris, twice, and now Brussels, we know. We cannot ignore that terrorism is here to stay. To say so is not to play the doomsayer nor the sorcerer's apprentice. It's the reality we need to face: The battle against jihadism will be a long one.

This assessment isn't intended as a smear campaign against the police or the intelligence services' work. Each terrorist cell dismantled, each arrest, like that of Salah Abdeslam in Brussels last week, represents an only natural sense of relief. The strength of democratic societies lies in their ability to go on as "before." By doing so, they thwart the jihadists' ambitions to provoke reprisal attacks against European Muslims and to create as many mini-civil wars as possible in Europe.

We shouldn't, however, harbor illusions. It's going to take time, years, before we defeat jihadist terrorism. In healthy democracies, political leaders and governments should tell it like it is. They don't, and are therefore hiding part of the truth.

Easy answers are lies

There's no magical recipe and no easy solution, two things we're used to having in our impatient, consumer-driven societies.

Those among protest parties or candidates - from the National Front here in France to Donald Trump, and others - who pretend otherwise are irresponsible liars. They're playing with the victims' pain. To say that we only need to flatten ISIS-controlled cities in Syria and Iraq with bombs is absurd, as this would instead create more wannabe jihadists. To say, as Marine Le Pen's National Front does, that we only need to close borders inside the EU to put an end to European jihadism, is a simplistic hoax. Weapons and explosives have been proliferating in our countries for a long time, while user manuals circulate on the Internet. We don't need any seller of illusions in this ongoing fight.

We should instead acknowledge the situation's complexity, on two levels. ISIS has in all likelihood forged sophisticated logistical networks inside Europe, with the aim of carrying out simultaneous attacks in different European cities. No mollycoddling here: The fight requires increased means for the police and intelligence services. Efficiency calls for reinforced coordination at a European level. Alas, the Union, already unable to unite in the face of the migrant tragedy, is in a regressive phase, which makes it even more vulnerable.

But European jihadism, though it stems from endogenous causes, is also fuelled by Middle Eastern chaos. To extinguish terrorism at home, we need to solve the Syrian and Iraqi tragedies. Again, this will probably take years. Again, although Westerners share part of the blame for these ongoing troubles, Europe is nowhere to be seen in fixing them, barely an actor alongside the U.S. and Russia. Its incompetence is evident in its lack of strategic vision, in the Middle East and elsewhere. This only adds to its vulnerability.

For our continent, the battle against terrorism means first facing the truth.