Riyadh: Nader al-Mutairi stiffened his shoulders, clenched his fists and said, “Let’s do our mission.”

Then the young man stepped into the empty lobby of a clinic, intent on getting the phone number of one of the young women working as a receptionist.

Asking a woman for her number can cause a young man anxiety anywhere. But in Saudi Arabia, getting caught with an unrelated woman can mean arrest, a possible flogging and dishonour, the worst penalty of all in a society where preserving a family’s reputation depends on faithful adherence to a strict code of separation between the sexes.

The sun was already low in the sky as Nader entered the clinic. Instantly, his resolve faded.

His shoulders drooped, his hands unclenched and his voice began to quiver. “I am not lucky today; let’s leave,” he said.

It was a flash of rebellion, almost instantly quelled. In the West, youth is typically a time to challenge authority. But what stood out in dozens of interviews with young men and women here was how completely they have accepted the religious and cultural demands of the Muslim world’s most conservative society.

They may chafe against the rules, even at times try to evade them, but they can be merciless in their condemnation of those who flout them too brazenly. And they are committed to perpetuating the rules with their own children.

That suggests that Saudi Arabia’s strict interpretation of Islam, largely uncontested at home by the next generation and spread abroad by Saudi money in a time of religious revival, will increasingly shape how Muslims around the world will live their faith.

Young men like Nader are taught they are the guardians of the family’s reputation, expected to shield female relatives from shame and avoid dishonouring their families by their own behaviour. It is a classic example of how the Saudis have melded their faith with their desert tribal traditions.

To them, prayer is essential. Jihad is too, not the more moderate approach which emphasises doing good deeds, but the idea of picking up a weapon and fighting in places like Iraq and Afghanistan. The concept is such a fundamental principle, so embedded in their psyches, that they do not see any conflict between their belief in armed jihad and their work as security agents of the state.

They earns about 4,000 riyals a month, about $1,200, not nearly enough to become independent from their parents.

Each of these young men have the requisite mustache and goatee, and most of the time dresses in a traditional robe. But on weekends, they opt for the wild and crazy guy look, often wearing running pants, tight short-sleeved shirts, bright colours, stripes and plaids together, lots of Velcro and elastic on their shoes.

In Western-style clothes, they seem smaller, and a touch on the pudgy side. Nader says softly, “I don’t exercise.”