LONDON – Among the most chilling developments in the rise of the Islamic State is that so many citizens of Western countries have joined the group’s ranks, becoming suicide bombers and beheading hostages. Why do hundreds of Muslims, many of them educated and from middle-class backgrounds, leave comfortable Western democracies to join a brutally barbaric movement? What makes young men and women susceptible to the extremist Islamist message?

As he watched the rise of the Nazis in the 1930s, Sigmund Freud described the dangerous appeal of authoritarian leaders and the satisfying self-aggrandizement that their followers experience when they subsume their personalities in an ideology or group. For those acolytes, freedom is a psychologically burdensome condition. As one of Freud’s disciples, Erich Fromm, famously argued, the urge to escape the demands of free choice – by adopting rigid beliefs or norms of conformity – can be especially compelling for those whose sense of a strong autonomous identity or a capacity to think for themselves is not fully developed.

The contemporary democracies from which Western jihadis defect offer an unprecedented degree of freedom. It is hard to think of a form of political community that requires so little allegiance from its members, proposes so few shared norms, and enforces so few behavioral guidelines. In nearly every aspect of our lives – morals, manners, sexuality, family structure, careers, and religious beliefs – we Westerners are essentially free to do as we like.

This may seem like a highly desirable state of affairs, conducive to the cultivation of a good life. But in the last few decades, Western democracies have been undergoing a marked identity crisis, manifested in an unwillingness to articulate organizing ethical principles or to project democratic values onto the international stage.

Internally, there is widespread disengagement from the political system and a growing sense of radical disaffection among some citizens, especially the young. There also appears to be a widespread increase in psychological dysfunction, ranging from anorexia and obesity to attention deficit hyperactivity disorder and widespread depression, all of which have led to a massive increase in the consumption of psychoactive drugs.

Such symptoms and syndromes cannot be understood in purely economic terms, if only because they are as prevalent among the middle class as they are among the poor. What is possible, however, is that the Western ethos of unhampered freedom and permissive tolerance fails to provide some people with the psychological scaffolding needed to construct an identity that can cope with the demands and pressures of constant individual choice.

We develop our identities in relation to others. The incorporation of cultural assumptions, ideas, and aspirations structures our perception of the world and provides us with psychological and moral orientation. In today’s open, multicultural societies, the need to choose is ever-present, whether the issue is banal (Which toothpaste should I buy?) or essential (Where do I find sources of purpose or meaning in my life?). But, with no shared cultural norms on which to base decisions regarding, say, how to achieve wellbeing or to direct one’s life, how can one distinguish between good and bad choices? What counts as right or wrong, serious or spurious?

In a sense, Westerners who choose to embrace fanatical Islamist ideology are an extreme manifestation of a much wider phenomenon. The Islamic State’s ruthlessly rigid creed relieves its followers of the disorienting burden of autonomous thought or choice. Fromm remains relevant: The flight into the embrace of a virulent movement like the Islamic State is also an escape from freedom by its discontents.

Some of the jihadis’ statements make the connection explicitly: "The cure for depression is jihad,” one Western recruit declares in an Islamic State video. "Feel the honor we are feeling. Feel the happiness we are feeling.” Another one simply states: "No to democracy.” Democratic ennui creates the conditions for radicalization, and the extreme Islamist movements know very well how to exploit it.

The seductive call of extremism will not be silenced with pleas to fundamentalist imams in European mosques to stop indoctrinating young Muslim men. Initiation into Islamist ideology needs to be countered by a much stronger initiation into the culture of democracy and its fundamental values – and by a much stronger affirmation of these values within our political discourse.

It is through increased confidence and conviction, rather than bland tolerance, that democratic societies can counter the appeal of fanatical causes and their charismatic leaders.

Eva Hoffman, the author of Lost in Translation and After Such Knowledge, is a former editor of the New York Times.