A particularly dramatic moment came in 1938, when Mexico's President Lázaro Cárdenas decreed that the country's foreign-controlled oil fields would be nationalized and the country's oil industry placed in the hands of a state monopoly, Pemex. American industrialists with interests in Mexico were outraged. They demanded that President Franklin Roosevelt intervene, with military force if necessary, as previous U.S. governments had done when Latin American governments had threatened U.S. business interests. Roosevelt refused, and negotiated a settlement, respecting Mexico's sovereignty while ensuring that private interests were compensated. This turning point in U.S.-Mexico relations made a strong impression on the young Carlos Fuentes, who was impressed with Roosevelt's diplomacy in reconciling the opposing parties. At the same time, Fuentes was made newly aware of his own identity as a Mexican in a foreign country.
While fulfilling his government duties, he pursued a literary career in his spare time. With the success of his novel, Where the Air is Clear, Carlos Fuentes could afford to leave the foreign service and pursue a career as a full-time writer. In 1962 he published The Death of Artemio Cruz, an epic panorama of Mexican history from the revolution to the present. This work, inspired in part by the stories his grandmothers had told him of the revolution and its aftermath, has become an acknowledged masterpiece of world literature and one of the signature works of el boom, a period of intense creativity in Latin American fiction, when writers like Fuentes and his friend, the Colombian novelist Gabriel García Márquez, captured the imagination of readers around the world.
Fuentes continued to write novels throughout the 1960s and '70s, including The Good Conscience, A Change of Skin, and Aura. In addition to his fiction, his journalism and political commentary made Fuentes one of the most recognizable public intellectuals in the Spanish-speaking world. This visibility also created difficulties. For many years he was denied a visa to enter the United States, as were many other prominent European and Latin American intellectuals, presumably for his criticism of American foreign policy, although no reason was ever given publicly.
Fuentes presented a lifetime of reflection on the shared cultural heritage of the Spanish-speaking countries in a television series, The Buried Mirror. His companion volume for the series proved immensely popular around the world.
Fuentes continued to produce novels, including The Hydra Head and Distant Relations. His novel, The Old Gringo, concerned the fate of the U.S. writer Ambrose Bierce, who disappeared in Mexico in 1913 during the revolution. The novel became a bestseller in the United States in 1985, the first novel by a Mexican author to achieve this status. A film version, starring Gregory Peck and Jane Fonda, appeared in 1989. The same year saw the success of Fuentes's novel Christopher Unborn, a philosophical fantasy told from the point of view of an unborn child who will enter the world on the 500th anniversary of the European discovery of America. These were followed by Diana: The Goddess Who Hunts Alone and The Crystal Frontier. Recent novels include Inez, and The Years with Laura Diaz, another saga of 20th century Mexican history, as seen through one woman's very long life.
A collection of essays, This I Believe: A Life From A to Z, received the Prize of the Royal Spanish Academy for Best Book of 2004. The same year, he published Contra Bush, a critique of the U.S. administration. He continued his meditations on history and public affairs in his last works of fiction. The Eagle's Throne (2006) is a mischievous satire of Mexican politics set in the not-too-distant future. His 2011 novel Destiny and Desire threads a tale of friendship between two old school friends through a dense tapestry of fantasy, history and mordant reflections on the state of contemporary Mexico.
With his wife, Mexican television journalist Sylvia Lemus, Fuentes divided his time between homes in Mexico City and London, England. Fuentes had one grown daughter by a previous marriage. The two children of his marriage to Sylvia Lemus died in adulthood of natural causes. Carlos Fuentes died in Mexico City at the age of 83.