On the other, populist voices say Islam is a religion of violence and that all Muslims are a potential threat.

Still others say that to hold any debate on the subject alienates people and plays into the hands of extremists.

But if responsible politicians don’t take part in this discussion with one another and with the general public, fear and ignorance will lead to more votes for far-right parties and deeper divisions.

Let’s make one thing clear: both points of view - that Islam has nothing to do with Islamism, or that they’re the same thing - are untenable. The first one pretends there’s no problem. The second one says it’s unsolvable.

French president Francois Hollande fell into the first trap when he said the Charlie Hebdo terrorists have nothing to do with Islam.

That’s the politically correct view.

That’s the view of leaders who want to reassure people that tougher security measures alone will solve the problem.

But it is obvious that since the last big terrorist attacks in Madrid and London, the number of radicalised Muslims in Europe has increased and there is more at stake than a mere criminal problem for the police and intelligence. There is no doubt the terrorists arise from Muslim communities and their acts are based on certain interpretations of Islam.

It’s equally untrue to say - the populist line - that Muslims per se pose a threat.

The overwhelming majority of Muslims are decent people who don’t condone violence and who adhere to moderate, or even secular, currents of thought in Islamic culture.

If we accept the discourse that Islam is a malevolent monolith which wants to bring down the Western liberal civilisation we create 20 million false enemies in Europe.

Meanwhile, there’s another common fallacy to consider.

We’re often told that jihadist radicals are the core of the problem.

It’s true that they are a concrete, immediate, and visible threat. But - and we don’t mean this to sound cynical vis-a-vis the victims of their crimes - the fight against terrorism is a tactical, or even a technical, issue.

At the moment, our security and intelligence services are not sufficiently equipped to cope with the problem.

But they know what they need to do and it’s a matter of time before their budgets, capabilities, and legal mandates are increased to adequate levels.

The strategic problem that we ought to consider is: Why are European Muslims prone to fundamentalist thinking, radicalisation, and hostility toward non-Muslim communities?

Of course, these elements exist in other minorities, or, indeed, in the European majority, which increasingly espouses extremist far-right and far-left views.

But we are analysing the Muslim minority, where sociological research shows that European Muslims are prone to these trends more than we’re happy to admit.

In his article, Religious Fundamentalism and Hostility against Outgroups, recently published in the Journal of Ethnic and Migration Studies, Dutch sociologist Ruud Koopmans notes that Islamic fundamentalism is widespread in Europe.

In a survey carried out with respondents from six Western European countries in 2008, almost 60 percent of Muslims agreed with the idea they should return to the roots of Islam.

Sixty five percent say religious law (sharia) is more important for them than the law of the country in which they reside and 75 percent believe there is only one legitimate interpretation of the Koran.

At the same time, 57 percent of Muslims don’t want homosexual friends, 45 percent don’t trust Jews, and 54 percent believe the West wants to destroy Islam.

Analogous figures for Christian respondents are much lower, by a factor of more than 10.

This data is backed by other research, for instance, by the Pew Research Center. It underlines the fact that the preponderance toward fundamentalism among European Muslims and the hostile behaviour it breeds lie at the heart of the problem.

In this context, we have to diligently look for ways to support those tendencies among Muslims which lead to adherence to liberal democratic values.

The key and irreplaceable role in this effort will belong to Muslims themselves and especially to that moderate, liberal, or secular minority which rejects fundamentalism.

Radko Hokovsky is director of European Values, a Czech think-tank. Jakub Janda is deputy director