In All American Girl, a world premiere from InterACT Theatre Company, radical Islam doesn’t take hold of its main character’s life all at once. For Katie, or Karima, as she comes to be known, Islam follows a conservative Christian upbringing, volunteer work in Boston’s slum-poor Dorchester neighborhood and a stint at Fordham University. When she meets Igbal, a brooding Indian immigrant and wrestling champion, he educates her on the ways Muslims are brutalized by Hindus in his home country.

But he’s no extremist — radicalism is something they find together. It gradually chokes them only after a series of disappointments and heartbreaks, a “tapeworm,” Katie says, that consumes them from within.

Written by Wendy Graf and directed by Anita Khanzadian, the one-woman play draws inspiration from recent, real-world accounts of teenagers and young women seduced online and radicalized into jihadist fighters. One of these — that of a 19-year-old Colorado woman arrested as she prepared to fly to Syria to marry a Tunisian man and fight for the Islamic State — is detailed in the program, a faux newspaper detailing atrocities committed against Muslims, the kind that come to obsess Katie as she trembles on the cusp of extremism.

Graf says in the press notes that she also was fascinated by the wife of Tamerlan Tsarnaev, the elder Boston Marathon bomber, whose friends expressed astonishment that this apparent girl-next-door could be mixed up in such an ugly business.

All American Girl is notable for taking the audience behind these bewildering headlines, crafting a layered narrative that traces Katie’s progression, starting with her average childhood in a Massachusetts suburb, entirely in her own voice. Katie is portrayed at alternating performances by Annika Marks and Jeanne Syquia (the latter performed on the night reviewed, although Marks takes over for the remainder of the run).

Drawing us in with a frank, warm, easygoing manner, Syquia charts the play’s leapfrogging chronology on a pair of chalkboards that come to function as a map of her life, as if by tracking dates and place names closely we can pinpoint the exact moment when she crosses over into terrorism. Joseph Slawinski’s sound design lets us slip seamlessly among these memories, easily evoking an Indian marketplace and a New York subway platform.

Syquia makes her character so appealing and sincere, and her concerns so urgent, that Katie’s choices never stretch beyond the bounds of credulity. Only much later do they strain sympathy. Syquia adeptly portrays a range of diverse ages and characters with precise accents, from a Nicaraguan housekeeper and a Southern preacher to a host of Indian relatives. None, however, is as nuanced as Katie herself: Igbal, who eventually becomes her husband, remains an often unsympathetic cypher, and the pastor follows a familiar trajectory of hypocrisy. Her parents are mere shadows.

But through Syquia, we see Islam evolve from an initially positive force, whose modesty she finds “kind of hot,” to a cultural badge that starts to push aside other forms of self-identification.

In turn, Katie’s compassion, her most defining trait, begins to harden and mutate: Ironically, if she were less sensitive to injustice, she might be less prone to fanaticism. “Isn’t doing nothing in the face of violence itself a form of violence?” she pleads with the audience on the eve of committing such an act. To her, extremism becomes a last resort to shake awake an undeniably apathetic public.

One of Graf’s most intriguing contentions is the play’s implicit argument that America’s terrorists, even those foreign-born, might be homemade. In a post-9/11 world, Iqbal struggles to find work and keep housing, and sees his dreams quashed because of lack of citizenship. He’s consistently other-ized. Treat aspiring Americans as outsiders long enough, the play warns, and they might prove you right.

GO! InterACT Theatre Company; Lounge Theatre, 6201 Santa Monica Blvd., Hollywood; through Aug. 30. (818) 765-8732, interactla.org.

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