WHAT would it take for a studious American teenager, the son of hard-working Iranian immigrants, addicted to surfing, his friends, his stoner way of life, and girls, to forsake all of that and become a radicalised Muslim? The question is explored brilliantly in Laleh Khadivi’s third novel, the final part of her Kurdish Trilogy.

Rez Courdee, born into a life of Southern California privilege, is a grade-A student who, introduced to surfing and joints by his three close friends – Peter, James and John, ‘the apostles’ – takes to this new life so eagerly that he begins to miss classes. He discovers girls; he wonders where surfing has been all his life.

Rez and his friends head for the Mexican Pacific to surf but through no fault of Rez’s the trip ends badly, to his friends’ fury. Rez’s relationship with two of them is sundered; what he does not – could not – know is that the episode will set in motion of sequence of events that will change the course of his life.

He hangs around with a new circle of friends: the charismatic Arash and his crew – Yuri, Omid, Cyrus. He feels as if he belongs, and in time he meets a girl, Fatima, a devout Muslim. But external events begin to alter ordinary Americans’ views of their Muslim neighbours: firstly,the bombing of the Boston Marathon, in which three people die and scores more are injured; and, secondly, a massacre carried out at a shopping mall by six attackers – from Yemen, Iraq, Saudi Arabia – kills 83 people.

Suddenly, Muslims are regarded with suspicion. Rez is not spared. “Sometimes nothing more than extra-long stares”, writes Khadivi, “the eyes asking, ‘Mexican? Middle East? Where from? Should I be scared? Are you the same evil?” Later, Rez, at a petrol station with Fatima, will feel another stare, from a grandmother nearby: the look manages to say both ‘—— you’ and ‘Don’t kill me’.

The novel is about Rez’s long search for an identity. Fatima, undeceived, scorns his all-American persona. “You are kidding yourself if you really believe that”, she tells him. “You can only be American if you turn into one. Which means a new name, a new nose, new skin, new tongue, new everything. Otherwise you are an immigrant, or the child of an immigrant, and this is not your home”.

Returning from an innocent trip to Indonesia, he is roughly questioned at the airport. “Every day someone with malicious intent for the innocent people of this country walks or flies or drives across our borders”, an official tells him. He adds: “The people you come from, your mother, your father, their families, the people you know at your fancy school, the rich Indian and Lebanese and Syrians just like you, are not the pride of this country … The American dream will never play all the way out for you. Do you understand?”

Rez has decided to explore what it means to be a good Muslim – to pray, to believe, to have rules and guidelines, to know God. But he reads the Koran and researches his people’s history with the West, and these and other factors make him easy prey for sinister figures who say that America is no good country, but that the Caliphate now being established in Syria will be “a good country”.

Khadivi handles Rez’s search for belief and belonging is handled with sensitivity and insight. She depicts his carefree, surf-and-girls self, the joshing language of California teens – “dude”, “sweet”, “totally” – with care; and the unerring precision of her prose draws you, piece by piece, into Rez’s orbit and makes you concerned for his welfare once the skies darken.

It’s interesting to read A Good Country alongside John Updike’s much-praised 2006 novel, Terrorist, in which a New Jersey high schooler, 18-year-old Ahmad Mulloy, a Muslim, sets out on his own journey towards jihad. As Shiraz Maher, of the International Centre for the Study of Radicalisation, King's College London, wrote in The Guardian a couple of years ago: …”Strip away all the grievances and myriad individual triggers that might drive an individual to join an extremist group and you find underlying issues of identity and belonging”. Khadivi’s book is a potent, awful reminder of this.