Stéphane Hessel: Résistant and UN diplomat who became a hero of the left in his nineties

Few people achieve global celebrity in their nineties. In 2011, at the age of 93, Stéphane Hessel, French resistance hero, diplomat, poet and essayist, became a worldwide bestseller and patron saint of the left-wing "indignant" protests in Europe and the United States. His tiny pamphlet Indignez-vous! (Get Angry! Or Time for Outrage), first published in France in October 2010, sold 4 million copies in over 100 countries. His spiritual "children" include the "Occupy Wall Street" movement and Beppe Grillo, the comedian who led the populist revolt against the élites of both left and right in the Italian elections last weekend.

Hessel, who died in Paris aged 95, called on younger generations to recapture the spirit of resistance to the Nazis and fight for the "values of modern democracy" against the "insolent, selfish" power of money and markets. His message – "indifference is crippling; be angry; revolt, peacefully, for what you believe in" – struck a nerve with those who felt that poor-to-middling people and welfare states were being unfairly punished for the economic collapse of 2007-08.

Hessel was not alone in being astonished by his book's success. The 19 pages of interviews were occasionally inspiring but often repetitive, unoriginal and simplistic. They included a lengthy, passionate digression criticising the Israeli government's treatment of Gaza. Hessel said last year that his book was successful because it had accidentally stumbled on an "historic" moment. "Our societies have lost their bearings," he said. "We are looking for new ways forward – ways of making sense of the human story." Even the most fervent admirers of Hessel's book would be hard-pushed to discover "new ways forward" in the text.

The worldwide triumph of the book angered many people on the Right in France, including President Nicolas Sarkozy. It infuriated the French Jewish lobby, which had long accused Hessel of being anti-semitic, despite his own half-jewish background. The book also generated unproven suggestions that Hessel's war record was not all that he claimed.

Stéphane Frédéric Hessel was born in Berlin in 1917. Although global celebrity arrived late, his early life was interwoven with many of the great events and great names of the 20th century. After his parents emigrated to Paris in 1925 they mixed with the movers and shakers of the modern movement: Marcel Duchamp, Man Ray, Le Corbusier, Picasso, Max Ernst and André Breton. His parents, Franz Hessel and Helen Grund, were two-thirds of a ménage à trois with the writer Henri-Pierre Roché – a relationship later described in the classic François Truffaut movie Jules et Jim.

The young Stéphane studied for a year at the London School of Economics in 1934-35 before returning to France, where he was granted French citizenship. His first love affair was with Jeanne Nys, the sister-in-law of Aldous Huxley, who was 17 years older than he was.

In 1939, to his mother's fury, he married Vitia Mirkine-Guetzevitch, a young Russian-Jewish emigrée. They had three children after the war: Anne, Antoine and Michel. Mobilised in September 1939, Hessel's unit surrendered to the Germans without fighting in June 1940. He escaped, and found Vitia in Toulouse before travelling to London, via Africa, in 1941, to join Charles de Gaulle's Free French movement.

Although retrained in Britain as an aircraft navigator, he joined De Gaulle's intelligence unit, the Bureau central de renseignements et d'action (BCRA). In March 1944 he was flown back to France to help distribute radio transmitters as D-Day approached.

Hessel was captured in July 1944 after another agent betrayed him to the Gestapo under torture. He, in turn, was tortured and revealed information to the Germans. This is the origin of some of the recent claims that he was no true Resistance hero.

Hessel was deported to Buchenwald with 36 other captured French, Belgian and British agents. All but three were executed. Hessel and two others survived because a German camp doctor switched their identities to those of prisoners who had died in medical experiments. After narrowly avoiding hanging for a first escape attempt, Hessel broke out of a train transferring him to the Bergen-Belsen camp in April 1945 and reached the American lines.

After the war he retrained as a diplomat. His first job was on loan to the United Nations, then based in Paris. He was secretary to the committee which drew up the UN's universal declaration on human rights in 1946-1948. He went on to represent France in the UN on human rights and social questions before joining the staff of the moderate Socialist reforming foreign minister and prime minister, Pierre Mendes France, in the mid-1950s. After a posting to the newly independent Algeria from 1963-69, he worked in the UN in New York and then, in 1977-81, as French ambassador to the UN in Geneva.

His wife Vitia died in 1985. Two years later he married Christiane Chabry, who survives him. Hessel retired in 1993. He remained active in moderate left-wing politics and became an increasingly passionate campaigner for Palestinian statehood.

His central message in Indignez-vous! was to exhort young people to apply the lessons of the 20th century to the 21st. "When something makes you want to cry out, as I cried out against Nazism, you become a militant, tough and committed," he wrote. "You become part of the great stream of history ... and this stream leads us towards more justice and more freedom but not the uncontrolled freedom of the fox in the hen-house."

John Lichfield

Stéphane Frédéric Hessel, war hero, diplomat and writer: born Berlin 20 October 1917; married 1939 Vitia Mirkine-Guetzevitch (died 1985; one daughter and two sons), 1987 Christiane Chabry; died Paris 26 February 2013.