I’ve been raving about Viet Thanh Nguyen’s extraordinary debut novel, “The Sympathizer,” since it appeared last March, so I was thrilled to see it win the Pulitzer Prize for fiction on Monday.

Nguyen’s book is a cerebral thriller about a Viet Cong spy who flees Vietnam during the fall of Saigon and comes to California, where he continues to report back to his masters for years. It’s chilling and moving — and sometimes very funny.

The Pulitzer judges praised the novel as “a layered immigrant tale told in the wry, confessional voice of a ‘man of two minds’ — and two countries, Vietnam and the United States.”

Nguyen was 4 when his family made a harrowing escape from Vietnam. In 1975, as the communist army overran his small village, his mother took him and his older bother and walked 120 miles so that she could reach her husband, who was away on business. They escaped on a refu­gee boat and eventually reached Guam and then, later, the United States.

I had the pleasure of interviewing Nguyen via Skype (watch here), and I met him in person when he came to last year’s National Book Festival in Washington (watch here). Debut novelists are rarely invited to speak at the festival, but now that invitation looks particularly prescient.

In addition to writing a brilliant novel, Nguyen, who teaches English and American studies at the University of Southern California, is also an in­cred­ibly gracious person. On Monday night, when we corresponded by email, and he was typically modest about what he has accomplished:

“I’m thrilled, honored, surprised to win this award, but I can never think of such an award as something that I merited on my own. My novel is made possible by the heroic struggles of many thousands of people before me who fought for equality, social justice and equal representation for all, in society as a whole and in the literary world in particular. The novel is also made possible by the many writers, remembered and forgotten, who have blazed the path for today’s minority writers, writers of color, Asian American writers, Vietnamese American writers. It would take a book to acknowledge the sacrifices of everyone who has worked to make this moment and my existence as a writer possible.”

For Peter Blackstock, Nguyen’s editor at Grove/Atlantic, the Pulitzer Prize confirms what he felt when he took a chance on a once unknown writer.

“I’m over the moon to hear this news,” Blackstock said via email. “I fell in love with this novel, as did our publisher, Morgan Entrekin, and others here, from the moment I read it on submission. I was so pleased to be able to publish it, and to hear this news today is just completely staggering. I’m thrilled for this immensely talented writer, and happy to have played a part in bringing this book to the world.”

The paperback edition of “The Sympathizer” came out last week, but the cover already has to be updated to reflect this well-deserved recognition. The publisher doesn’t mind. Grove/Atlantic has gone back to press for 40,000 additional copies.