"She's a very pragmatic woman - and that's her greatest weakness in my eyes," says Cyrille Lachèvre, a confidant of Ms. Lagarde as her biographer and as the business editor of the conservative Paris newspaper Le Figaro. "It's hard to know what she really thinks, and what are her ideas. … It's a very large question mark."
An outsider makes her way in
Beyond her persuasiveness, what convinces leaders that she is the woman for the moment is the unlikely trajectory of her life and career. When she got the call in 2005 from prime minister Dominique de Villepin to join France's conservative government, she had already established herself as a figure of extraordinary independence from conventional French thought - and, for much of her life, from France itself.
Raised in Paris by middle-class academics, she became a national-level swimmer and suffered the death of her father as a teenager, then made the very un-French move of going to Bethesda, Md., for finishing school. She studied law at the very left-wing University of Paris X Nanterre, but then returned to the States as an aide to a Republican congressman.
Her law career, with the Chicago firm Baker McKenzie, was meteoric: She joined at age 25; by 1999, at 43, she was the chairwoman, and had transformed the firm's structure and culture.
In the dying days of Jacques Chirac's presidency, she sailed through a series of minor cabinet posts as something of an outsider: A non-drinking vegetarian who liked free markets and preferred to address her staff in English, Ms. Lagarde was out of step with the anti-American Gallic defiance of the day. Her staff called her "Christine the Guard," mocking both her linguistic tastes and her stubbornness, or simply "the American."
But with the election of Nicolas Sarkozy in 2007, she became part of a movement, and not just because Mr. Sarkozy was also a pro-U.S. non-drinker. The new President, a child of immigrants educated at non-elite schools, purged his cabinet of the Énarques - graduates of the École Nationale d'Administration, which produces most French bureaucrats and leaders. He preferred lawyers like himself. Ms. Lagarde moved from fringe to centre, and took charge of reforming the French economy.
She stood out as a powerful woman in a macho cabinet and, more importantly, one with no patience for French economic pieties. Employment laws were a particular object of scorn: The 35-hour work week (invented in part by her friend Mr. Strauss-Kahn as a minister in a 1990s Socialist government) was "the ultimate expression of our historic tendency to see work as a form of servitude" - a "tradition of contempt" for work "that reaches back to the ancien régime."
Provoking months of outrage, she even called for an end to contemplation: "France is a country that thinks," she said. "But enough thinking now! It's time to roll up our sleeves."
That seemed a bit rich to observers who pointed out that she enjoyed two maids, two private chefs, a huge apartment, an official boat to take her along the Seine from ministerial to parliamentary offices and a staff of 41, all on the public payroll. She was also one of the most fashionable women in France, turning heads with daring wardrobes, in skin-tight silk and body-length white patent leather, by her country's most famous designers.
And her personal life, while free of the kinds of dark rumours attached to Mr. Strauss-Kahn and a number of her cabinet colleagues, did not meet France's far more conservative standards for women. Divorced, with two grown sons, she has admitted she was never primarily interested in being a wife or mother. She now reportedly lives with French businessman Xavier Giocanti. "I had to accept that I could not be successful at everything," she said this year. "You draw up priorities, and you accept a lot of guilt."
That said, she doesn't consider her sex secondary to her success. Indeed, all else being equal, she'd hire a woman ahead of a man.
"Women inject less libido and less testosterone into the equation," she told an interviewer months before the Strauss-Kahn controversy. "It helps in the sense that we don't necessarily project our own egos into cutting a deal, making our point across, convincing people, reducing them to a partner that has lost in the process."