One of the few Vietnamese Army officers who also saw substantial service in Ho Chi Minh’s National Liberation Army against the French, Tran Ngoc Chau made a momentous and difficult decision after five years with the Viet Minh: he changed sides. Although his brother Tran Ngoc Hien remained loyal to the North, Chau’s Buddhist training and his disillusionment with aspects of the communists’ philosophies led him to throw his support to the nationalists and assist the Americans. It was a decision that would cost him dearly when former military school colleague Nguyen Van Thieu, fearing a political rivalry, imprisoned Chau—by then a lieutenant colonel and the Secretary General of the National Assembly’s Lower House—despite popular sentiment and the support of Americans like John Paul Vann and Daniel Ellsberg. At every turn Chau stood on principle, however, opposing government corruption, refusing favoritism, and remaining steadfast in his dedication to democracy. His principles would cost him again when, after the fall of Saigon, he was imprisoned in a North Vietnamese re-education camp and even after release kept under continuous surveillance. His detailed memoir reveals an astute understanding of the Vietnamese political situation and national culture that failed to register with U.S. leaders—and offers valuable insights into how to cope with similar conflicts in the future. As Ellsberg has put it, “ *Vietnam Labyrinth* is unmatched, both for its narrative and for lessons to be learned for our current interventions.