At a cafe on the Place des Vosges, Natalia Gevorkyan is picking at a salade verte and thinking about betrayal.

It’s a central theme in the worldview of Vladimir Putin, the Russian president and a man who once spent many hours telling her of his life and his credo. It was natural for a KGB officer to suspect betrayal all around him, she says, and although Putin left the agency nearly two decades ago, he has never shaken its particular view of human nature. Yet today, an air of suspicion seems to permeate the Kremlin more than at any time since he came to power.

Gervorkyan was a co-author of an authorized biography of Putin, hastily slapped together in 2000, just after he became acting president. The book, “First Person,” was an early attempt at image-making and legend-building.

In hindsight, she says, all sorts of things jump out. Among them is the way Putin had an eye out for betrayal.

The dark mood of distrust that is reported to be pervasive within his inner circle almost certainly originates at the top. Political protest, police investigations, a capricious anti-corruption campaign, clan feuds and ambitions — all fuel it. Steadily, too, Putin’s poll numbers are eroding, as if the electorate itself is starting to betray the man in the Kremlin.

That’s, at least, how he would probably see it. “He suffers,” Gevorkyan says, from an inability to trust people — or, the people. And he comes from a culture that expects citizens to live up to the expectations of the authorities. In 1991, the head of the KGB — Putin’s old boss — said he took part in the failed hard-line coup against Mikhail Gorbachev precisely because the people were untrustworthy and no longer fulfilling their obligations to the state.

That attitude resonated with Putin (who told Gevorkyan that the coup leaders had their hearts in the right place, even if their plans were wrong-headed).

“The cooperation of normal citizens,” he told her 13 years ago, is “an important tool for the state’s viable activity.”

That isn’t as bland a sentiment as it sounds. It’s about the duty of citizens toward the state. But Putin is now a year into his third term as president, at the apex of that state, and the ground has shifted. The “viable activity” of the state is under stress — and the relationship between the state and a major part of its citizenry is in flux.

Putin’s approval rating — at 57 percent, according to the latest poll by the independent Levada Center — would be more than sufficient for any democratic politician, but in Putin’s system, as the analyst Kirill Rogov points out, it suggests an unacceptable opening for public doubt. A large majority of Russians say they don’t want Putin to run for another term in 2018.

Siege of Leningrad

Gevorkyan moved to Paris in late 1999 as a correspondent for the Kommersant newspaper. She was summoned back to work on the Putin biography after Boris Yeltsin resigned as president. With co-authors Andrei Kolesnikov and Natalya Timakova (today Prime Minister Dmitry Medvedev’s press assistant), she met with the new leader for 30 hours of interviews at his Kremlin office and in a former KGB safe house. Most of the book, which came out a few weeks later, consists of questions and answers.

Once back in Paris, she was to write an unflattering article about Putin’s first European trip, and he snubbed her after that. “His attitude is: If you are doing the book, then you are his forever,” she says. But she wasn’t his, and he saw that as betrayal, and now, even though she has parted ways with Kommersant, she still lives in France.

Betrayal is a Russian theme, and a KGB obsession, but it’s the particular trauma of Putin’s home town, St. Petersburg, once called Leningrad. Putin’s parents survived the 900-day siege of Leningrad during World War II, although an older brother died. His father was wounded and never fully recovered. When Putin was born, in 1952, his middle-aged parents doted on him.

But the city, and its inhabitants, still bore, in enforced silence, the burden of the wartime nightmare. Their survival, in the official telling, was a glorious Soviet victory. Even today, the main siege museum, just a few blocks from the apartment where Putin grew up, greets visitors with large portraits of generals and admirals in their dress uniforms. Upstairs, prominent photographs show plucky Leningraders playing soccer and volleyball.

In fact, 900,000 people died in Leningrad, many from starvation. Whether Joseph Stalin betrayed the city by insisting that it hold out is debatable, but residents undeniably betrayed one another. The historian Dmitri Likhachev, who survived the siege, described it as a time of cannibalism and of abandonment, when parents betrayed children and children betrayed parents.

Looking for a ‘roof’

The psychological trauma — probably prolonged by the official refusal to recognize it — weighed on the city for years afterward. Betrayal had been the worst sort of transgression, but it also had been a survival strategy.

“Only a few people are really close to me,” Putin told Gevorkyan, then added, without apparent prompting: “They have never betrayed me, and I have never betrayed them, either.”

Gevorkyan believes that far from being an ambitious careerist, Putin spent his life looking for a protector, what the Russians call a “roof.” The code of the roof comes down to loyalty to one’s own and a united front against the rest of the world.

Putin’s first clan was the KGB. With the Soviet collapse, he found a new roof in the reformist mayor of St. Petersburg, Anatoly Sobchak, for whom he went to work. When Sobchak lost a 1996 reelection campaign to his chief aide — who had run against him in an ultimate act of betrayal — Putin found a roof by taking a job in the Kremlin. Then, Gevorkyan says, the presidency became his roof, his means of protection.

That’s why she doesn’t expect him to give it up. Only betrayal by the people could remove him now.