The Sympathizer by Viet Thanh Nguyen

Set at the end of the Vietnam war, The Sympathizer is told from the point of view of a communist spy placed in the South Vietnamese military.  After the war, he immigrates to the US and continues his double life.  This is a book about duplicity—most obviously, that of the main character, who lies to everyone, but it is also about the duplicity of governments and the dishonesty between friends.  It is a challenging and sometimes disturbing book.  The Sympathizer won the 2016 Pulitzer Prize for Fiction, as well as a number of other awards.