Her name was Margaretha Geertruida "Grietje" Zelle. She was born in Leeuwarden in the Netherlands, her family wealthy until she was about thirteen. She married Captain Rudolph MacLeod, who had advertised for a wife in a Dutch newspaper. The couple moved to Java, at the time a Dutch colony, and had two children. The marriage was a disaster, not helped by the death of their son--or the fact that he was sleeping with a "native wife" and concubine. Eventually, they returned to the Netherlands, and the couple divorced in 1907. She took to the stage, claiming to be a Javanese princess who was raised Hindu. She had spent her time in Java studying local culture, and she performed what she claimed were native dances. She had any number of lovers, usually high profile ones, but as World War I approached, that began to seem less dangerous and more exotic. During the war, as a citizen of a neutral country, she was able to travel essentially where she pleased, which was also suspicious.
Here, she is Greta Garbo, herself a mysterious figure as far as the American public was concerned. She is Mata Hari, seductive dancer who has been wooing men to do her will. She works for Andriani (Lewis Stone), who runs a spy network. Mata Hari seduces soldiers into giving her information they aren't supposed to give to anyone, and she passes it on. Russian General Shubin (Lionel Barrymore) is infatuated with her, but Mata Hari has moved onto Lieutenant Alexis Rosanoff (Ramon Novarro). Shubin was business; Rosanoff is both business and pleasure. In fine old movie fashion, she starts out seducing him so that she can get information from him, but she really begins to fall in love with him. The problem, however, is that the French Secret Service, in the person of Dubois (C. Henry Gordon), is on to her, and it's only a matter of time before she is captured. And that's if her own people don't get her first.
We want Mata Hari to fit the story we have of her. We want her to be the cunning seductress, the woman who was the most clever spy in World War I. It was claimed at the time that her actions were responsible for the deaths of 50,000 French soldiers. She told the British that she was working as a French spy, so she was really executed for being a double agent. We don't want to consider that she may well have been lying about being a French agent, and the idea that she may not have been an agent for anyone is unthinkable. However, as the records have been unsealed, they have consistently shown that she was innocent. Certainly it's hard to imagine that she could have been responsible for remotely as many deaths as she was accused of having done. The pictures show that she was a lovely woman, though hardly exotic in appearance, and that even her "nude" poses probably involved body stockings. Very little of the legend of Mata Hari is real, and quite a lot of it comes from people picturing Garbo instead.
Of course, she is luminous in the role, whereas she would not have been in a more authentic characterization. It's hard to imagine Garbo as the mere victim of circumstance. On the other hand, I think many of her characters are more trying to steer a sinking ship. Garbo's version of Mata Hari became a spy almost on a whim. It sounded fun and exciting. In no version is she German, so it can't be patriotism. Garbo's Mata Hari seems to have been drawn to being a spy for the adventure of it, I think, and once there's something more important to her out there, she wants to go for that instead. However, she is unable to. Her performance of Mata Hari's performance at the end is that of a woman trying to shape the last hours of her life as best she can. From the beginning of the movie, her path was set, but she spends the whole of the movie making sure that she's the one doing the walking. It's not her fault that there is nowhere left to turn at that point.
At one point in the movie, Mata Hari performs what would be a despicable act even if it weren't for the spying she's doing meanwhile. Ramon Novarro has a picture his mother brought back from Lourdes, one he has sworn to keep a light burning under. Mata Hari needs the dark so her coconspirators can steal the messages he is supposed to be carrying, photograph them, and return them without his knowledge. But he has sworn to keep that light burning; he even has his valet take care of it while he himself is off performing his war-related duties. Mata Hari makes it a test of his love. If he loves her, he will extinguish every light. Including that one. He tells her that he will do anything she asks for their love, but he begs her not to ask that. (Maybe it's what Meat Loaf won't do?) And indeed, true love does not set such tests, so far as I am concerned. Naturally, the circumstances here are much more complicated, though the fact that it's about spying doesn't make it better.