Gérard Chaliand, an acclaimed writer on geopolitics, revolutions in the developing world and terrorism, whose dozens of books were informed by on-the-ground experience in conflict zones, died on Aug. 20 in Paris. He was 91.

His death, in a hospital, was announced by the Kurdish Institute of Paris, a Kurdish-rights advocacy group to which he belonged. His son, Roc, said the cause was kidney failure.

Mr. Chaliand (pronounced “SHA-lee-ahn”), who spent much of his life in France, taught at some of the country’s most prestigious schools — the École Nationale d’Administration and the École de Guerre — and at the University of California, Berkeley, and Harvard. His lectures on geopolitics drew top-level diplomats and officers. But his influence in the French-speaking world was based on an unusual attribute: He had actually been to the revolutions he wrote about.

Over nearly four decades, he spent time with guerrillas in Guinea-Bissau, Angola, Jordan, Lebanon, the Philippines, Afghanistan, North Vietnam, the Kurdistan region, Sri Lanka, Eritrea and elsewhere. He witnessed the beginnings of the Algerian revolt against France in the early 1950s. And he frequented revolutionary leaders like Che Guevara, Ahmed Ben Bella, Julius Nyerere and Sékou Touré as well as Amílcar Cabral of Guinea-Bissau, whom he particularly admired.

Mr. Chaliand acknowledged being attracted to insurrection, but he was there to observe, report and write. “Felt knowledge is irreplaceable,” he told France Culture radio in 2008.

That hands-on experience, particularly in the 1960s, led him to an early insight into the revolutions taking place in what was then called the third world: They had largely failed. They had not brought greater security, freedom or prosperity to the people they claimed to liberate. In the early 1970s, a time when optimism over the promise of liberation struggles still prevailed, particularly on the left, Mr. Chaliand’s report from reality was a cold shower.