When you hear that Hollywood is adapting a book like Viet Thanh Nguyen’s The Sympathizer, you worry. Published to raves in 2015, the searing debut novel set in the immediate aftermath of what Americans call the Vietnam War—but that, as Nguyen and the new HBO series both remind us, Vietnamese know as the American War—won a Pulitzer for what the committee described as “a layered immigrant tale told in the wry, confessional voice of a ‘man of two minds’—and two countries.” It’s a psychological thriller, a war story, a political satire, a cri de coeur, and an investigation of identity, sifted through a mesh of framing devices and unfolding largely within the fractured interiority of a man who has yet to discover who he is or what he believes.

How lu…