How do you balance lust and caution?

"Lust, caution" sounds like a cross between a road traffic sign and a porn film. In fact it is the English translation used as the title of a short story by the 20th century Chinese writer, Eileen Chang, and a 2007 film by the famous Taiwanese director, Ang Lee. The essence of both is loyalty and betrayal in war-torn China of the 1930s and 40s. The story is based on the life of a real woman spy, who seduced a leader of the Chinese puppet government working with the Japanese invaders so that Chinese nationalists could assassinate him. But Chang also draws on her own life, as she was also married to a member of that puppet government. Chang's writing in this story, and the other short stories contained in the Penguin edition pictured, is vivid, concise, waspish and 'warts-and-all'. A couple of examples: "Ah Fang was a tall girl, but she had buck-teeth too, and smiling eyes that were black and bright in a concave, wok-bottom face." "Mrs Lou wore eyeglasses. When she frowned her eyebrows formed an upside-down 'V'. Her face was like a dumpling made by a child that had been pinched and kneaded till the dirt from the hands got into the flour, making it sort of dirty white." Chang tells the story and doesn't waste words. I admire her writing and intend to read more of it. Ang Lee's film, known for its full-frontal lust, expands the short story, rounding out episodes that are only hinted at there. It is a beautifully-made and acted film, which won many prizes (but was snubbed by the Oscars). Some western critics think it is too slow, but I like the way the story evolves gradually and it is always beautiful to look at. Lust, caution could also sound rather moralistic as a title, but I don't sense that either Eileen Chang or Ang Lee are trying to make a moral point, they want to tell an intriguing story, in which real characters face difficult choices, especially Jiazhi, the girl at the centre of it all.