Lust, Caution

Lust, Caution (色、戒) was originally a short story by Chinese writer Eileen Chang. It was made into a movie by Ang Lee in 2007, starring Tang Wei and Tony Leung.

The story is set during the Japanese occupation of China in WW 2. Mrs. Mak is ostensibly an idle housewife who enjoys Mahjong and shopping. In fact, her name is Wong Chia-chi and she's a member of a Chinese Nationalist resistance cell who has infiltrated the household of Mr. Yee, a high-ranking member of the pro-Japanese puppet regime, in order to become his mistress and draw him into a trap. But Mr. Yee is a terminally paranoid man and stays on his guard at all times.

Tropes used in Lust, Caution include:

Cyanide Pill: Wong Chia-chi is given one when she joins the resistance cell in occupied Shanghai. When she is about to face capture by the Japanese, she reaches for it but decides to allow herself to be captured alive.
Downer Ending
Honey Trap: Basically the entire plot.
How We Got Here: The story begins as the assassination plot is nearing completion, only to jump back to four years earlier.
"It's Not Rape If You Enjoyed It"
Kick the Dog: When we first see Mr. Yee, he orders an underling to finish off a prisoner he has just finished interrogating, on the grounds that the Japanese didn't specify they wanted him alive.
- It's a bit more subtle than that. Yee says "give him a quick one" implying that by killing the man now they are saving him from more torture at the hands of the Japanese, who would eventually kill him themselves. This film doesn't have Kick the Dog style moral clarity.
La Résistance: The underground resistance cell that Chia-chi and her former classmates join in occupied Shanghai.
Les Collaborateurs: Mr. Yee and the rest of the pro-Japanese puppet regime.
Mirror Scare: Chia-chi closes a window, and she spots the reflection of Mr. Yee in it--he had been sitting in a corner of the room all along, but she hadn't seen him.
Properly Paranoid: Mr. Yee considers everyone a potential enemy, and he's right.
Rape Is Love: Mr. Yee is a brutal man whose idea of sex involves violent coercion, but Wong Chia-chi ends up falling in love with him anyway.
- This Troper sees it differently - it was only when Wong and Yee stopped having sex and started connecting on a more emotional level (in the Geisha house, for example) that Wong began to see his humanity. By all standards, Yee was a terrible human being, but he was indeed human, and at the last minute, Wong found herself unable to kill another human, particularly since she and the other conspirators had been so disgusted by Tsao's brutal death in Hong Kong.
Rasputinian Death: Tsao, Mr. Yee's underling in Hong Kong. His messy and protracted murder is the reason Wong Chia-chi splits up from the group until three years later.
The Revolution Will Not Be Civilized: The main difference between La Résistance and the Japanese oppressors seems to be that the Japanese are in power.
Shoot the Shaggy Dog: The plot is given away at the last moment by Wong Chia-chi, leading to the execution of her and pretty much the whole of La Resistance outside of the cold-blooded leader. All to protect the life of the rapist thug bastard she fell in love with and who, given the state of Japan's military fortunes by the end of the movie, is living on borrowed time anyway.
Slow Clap: At the end of the premiere of the group's patriotic play, one person rises and shouts "China must not die!" Soon everyone else stands and joins in.
Training Montage: Wong Chia-chi's training in the basics of spycraft.