A man of intellectual dynamism and conviction, an apostle of the high-tech future and a great seducer, Jean-Jacques Servan-Schreiber — or JJSS as he called himself — was France’s Mr Modernity, a Gallic champion for the French equivalent of Harold Wilson’s “white heat of technological revolution”.

A towering presence on the intellectual and journalistic scene from the 1950s through to the 1970s, he was also a political figure of considerable stature, whose ambitions were hampered by his lack of strategic sense, his refusal to yield on matters of principle and also by his membership of the Radical party, one of the non- ideological groupings that crop up in French politics and are sooner or later crushed between Left and Right.

Jean-Jacques Servan-Schreiber was born in Paris in 1924, the son of Émile Schreiber, a successful publisher who founded the financial newspaper Les Échos. He studied at the École Polytechnique, graduating in 1947. During the latter stages of the war, he served in the French Air Force in Algeria, which was then under the provisional government of de Gaulle, and he later went to Alabama to train as a pilot.

In 1953, after writing on foreign affairs for Le Monde, he and his mistress, Françoise Giroud, founded and edited a weekly current affairs magazine, L’Éxpress. Initially published as a supplement to Les Échos, it made no secret of its support for Pierre Mendès-France in his campaigns for peace in Indo-China and later in Algeria. The magazine quickly found a readership among young intellectuals of the day, and its contributors included Albert Camus, Jean-Paul Sartre, André Malraux and François Mauriac.

Short, dark with a crew cut, Servan-Schreiber cultivated a youthful ruthlessness and a love of shocking people well into his middle age. He performed physical jerks at his office in L’Express and delivered pep talks from time to time to his staff. For all his political and intellectual influence elsewhere, L’Express would be his greatest success as the first news magazine in what has since become a crowded field in France.

In 1956 Servan-Schreiber was called up for service in Algeria as a reserve officer, an experience which he described in his book Lieutenant en Algérie. It also contained an indictment of the use of torture — in which he was supported by his commanding officer, General de la Bolladière — and aroused the fury of the authorities.

Although L’Express had advocated the return of General de Gaulle in 1957 to remedy France’s political confusion and growing involvement in Algeria, Servan-Schreiber opposed de Gaulle’s return to power in 1958 because he considered that de Gaulle would be influenced by the Army in Algeria.

During the 1960s Servan-Schreiber tried in vain to have himself adopted as a political candidate in Normandy, Marseilles, Grasse, Brive and other constituencies. His star began to shine more brightly in 1967, however, with the publication of his book Le Défi Americain (The American Challenge). In it he argued that the US and Europe were locked in a silent commercial war that Europe, outclassed on all fronts, was bound to lose, and he called for European technological co-operation in a federal Europe as the only way Europe could face the challenge. In its first year the book sold more copies in France than any French book had done since the war.

The departure of de Gaulle in 1969 encouraged ServanSchreiber to try his hand at politics once more. It was not surprising that the Radicals, keen to enliven their somewhat moribund political machine, chose this able publicist as their secretary-general early in 1970 — the ever-flexible philosophy of Radicalism could accommodate a dose of Schreiberism.

His Pimpernel-like rescue of the Greek composer, Mikis Theodorakis, who was a prisoner of the Colonels and sick in hospital when Servan-Schreiber flew to Athens in April 1970, brought him a great deal of publicity. But it did not serve him altogether well; he had claimed more international backing than he really had, and there was a belief that he had promised too much in return for Theodorakis’s release.

Servan-Schreiber’s 1971 election victory at Nancy over the Gaullists — who supported their candidate in full force once the seriousness of the challenge became evident — was described by some commentators as the most important political event in France since Pompidou’s election as President.

Flushed with victory, he then decided that a Reformist candidate had to win the Bordeaux constituency which the French Prime Minister, Jacques Chaban-Delmas, had represented for many years, and which, as the constitution of the Fifth Republic ordained, he had resigned to a substitute on becoming a minister. The substitute having died, ChabanDelmas decided to contest the seat again. Unfortunately for Servan-Schreiber, the local Socialists and Radicals could not agree on, and did not want, a Reformist candidate. So Servan-Schreiber decided to stand himself, though, if elected, he said he would resign and continue as deputy for Nancy. His act appeared foolish and even Mendès-France criticised it. The fact that he won even 16 per cent of the votes was perhaps a feat. However, he submitted his resignation as secretary-general to the Radicals after his defeat; it was not accepted. In March he stood down temporarily. That, in October, he was able to win the presidency of the party could be said to show how much the Radical rank and file valued a man who, whatever his mistakes, had fire in his belly.

In January 1971 ServanSchreiber was obliged to abandon the direction of L’Express after protests by most of the staff that its editorial freedom was being damaged by his political activities. By June he was back in practical editorial control, though without the nominal title so long as he remained in politics. It was the packet of shares in the company that he and his associates held which won the battle. The editor and most of the heads of the editorial departments left.

Servan-Schreiber’s political activities continued unabated, however. He was one of the chief architects of Valéry-Giscard d’Estaing’s successful presidential campaign in 1974, and was duly rewarded with a cabinet seat as Minister of Reforms — a modernising portfolio if ever there was one. However, he was soon ejected because of his overzealous support of the campaign against French nuclear testing in the Pacific.

Servan-Schreiber’s role at L’Express ended in 1977, when he sold the magazine to Jimmy Goldsmith. He did, however, continue to argue for his ideas in writing. His next book was Le Défi Mondial (The Global Challenge, 1980) which widened its focus to include Japan.

In 1981 Servan-Schreiber acted as unofficial adviser to Gaston Defferre, Home Secretary in charge of decentralisation for the new Socialist Government. He was also one of the intellectual lights turned to by François Mitterrand in 1983, when the first two years of Socialist élan foundered amid massive financial crisis.

His own project at this time, an information technology and human resources centre in Paris, was wound down in 1985, its occasional but real successes having failed to justify its budget. He left Paris for Pittsburgh, so that his sons could be educated at Carnegie Mellon University, where he became head of international relations. He then returned to France at the end of the 1980s and devoted himself to his memoirs, the two volumes of which were published in 1991 and 1993.

Servan-Schreiber’s last years were troubled by a mental disease that affected his memory. According to his family, this never prevented him from continuing to take an avid interest in politics and current events, or from reading. However, his public appearances after his return from the US were rare. His name, though, remained synonymous with the intellectual buzz and glamour of modernising France.

Servan-Schreiber married, first, Madeleine Chapsal (dissolved 1960) and, second, Sabine Berq de Fouquières. She and their four sons survive him.

Jean-Jacques Servan-Schreiber, journalist and politician, was born on February 13, 1924. He died on November 7, 2006, aged 82.