PARIS -- Ever wonder what Leonid Brezhnev really thought of Jimmy Carter? Whom Brezhnev wanted as his successor? Why Anwar Sadat's plan to invade Libya in 1977 was suddenly called off? How sensitive Helmut Schmidt is about his father's being half Jewish?

All of this, and more, came to light here this week with the publication of a slice of memoirs by France's only living former president, Valery Giscard d'Estaing. In a book entitled "Power and Life," Giscard lifts the veil in a very selective manner on confidences made to him by these and other fellow holders of power.

Giscard's faith in what leaders whisper to each other is the most striking feature of this account. His descriptions of the networking aspects of leadership, of the small and exclusive club that exists at the top, seem to me to ring true. There is an "us against them" quality that inadvertently suggests why leaders of all political stripes and shades of all nationalities frequently lose touch with those they are supposed to govern.

Memoirs by fallen politicians are notoriously unreliable history. They are usually rife with retroactive justification and self-pity inspired by the public's failure to understand and support the grand schemes of great men.

These qualities are not absent from Giscard's book. But a certain rhythm of recent history also pulses through this volume, which provides useful insights into the changing nature of political leadership in western democracies over the past decade.

Giscard, the aloof technocrat elected to the Elysee palace in 1974 and denied reelection by a fed-up French electorate in 1981, highlights his similarities with Carter and Schmidt, who were also driven from office by the political and economic turbulence that shook the world at the turn of the decade.

Each of the three gave the impression of seeing public opinion as a hindrance to getting the job done. In diplomacy, in international economic cooperation and in other areas, each was ready to subordinate domestic politics and to go for a larger international payoff, either as a matter of principle or as intellectual gamesmanship.

This helped seal their political fates, as Ronald Reagan dispatched Carter, Helmut Kohl followed Schmidt and Francois Mitterrand defeated Giscard. This trio of successors is not likely to be accused by posterity of putting international considerations before domestic concerns, suggesting once again that history shapes leaders at least as much as leaders shape history.

In one of his best passages, Giscard recounts Brezhnev in 1979 asking for an opinion of Carter and then exploding that the American "is always writing me letters" that Brezhnev finds useless "and then insulting me in speeches that he thinks I don't know about." Who, the Russian leader demanded, did Carter take him for? "And who does he think he is?"

Brezhnev's choice in 1980 to succeed him was Konstantin Chernenko, Giscard is told by Polish leader Edward Gierek. When Yuri Andropov makes it instead, Giscard concludes that there are serious splits in the Politburo.

Another nugget turned up is direct confirmation by Giscard in this book that during his presidency France did not station civilian intelligence agents in the Soviet Union. He does not explain, but French concerns about the deep Soviet penetration of their intelligence service at that time probably would have made such an effort more dangerous than useful.

Giscard also confirms that he and Sadat discussed in detail Egyptian plans for the overthrow of Libya's Moammar Gadhafi in 1977. Sadat later told Giscard that the Carter administration learned of the plan on coming to office and blocked it. Giscard alludes, in less direct fashion, to approaches by his own emissary in February 1981 to the Reagan administration, which agreed to join forces with France to eliminate Gadhafi. Giscard's defeat took France out of that effort.

Only one confidence from Carter is quoted, and Giscard uses it to undercut the Georgian, whom he clearly dislikes. As the shah of Iran is about to flee in January 1979, Carter assures his fellow leaders that all will turn out well because the Iranian military will take control. Carter says this is a happy prospect because "our generals are on a first-name basis with them."

In contrast, Giscard wants it known how close he is to Schmidt. I can see no other reason for the long and sentimental description he gives, with the former chancellor's approval, of Schmidt disclosing to him the family secret that his father was half-Jewish. "Because of his position as chancellor," Giscard notes archly, "this was also a state secret."