The Girl from Perfume River by DS Holmes

It began when a newspaper editor assigned an investigative piece to an Asian-American reporter and became, with the discovery of her aunt's carefully typed memoir, a journey back in time to the final days of French colonial rule in Indochina where a young Vietnamese woman must choose between love and duty. When a priceless artifact is stolen from a Saigon museum, she searches for the valuable item without help from the police. Threatened by a crime organization, she and an American correspondent flee Saigon, pursued by hired killers. The Perfume River story is told from the Vietnamese woman's point of view. A variation on the story, set in 1951 during JFK and RFK's historic visit to the land of Vietnam, is available as the Watchman of Saigon and that tale is from the foreign correspondent's perspective.