Character Analysis
Vandamm almost out-suaves Thornhill.
Calm down. We said almost.
Still, he's a killer at heart who has no qualms about throwing his girlfriend out of a plane when he discovers she's working for the other side. We don't really get much insight into what makes Vandamm tick except that he's driven by his mission to wring important intelligence info out of George Kaplan. We don't even know what communist government Vandamm's working for. Instead, Hitch treats him as pretty much a textbook villain, one whose main goal is to make the hero's life a nightmare.
Sure enough, that's what Vandamm does from the time when we first meet him in the Townsend mansion until the very end of the film. He never believes that Thornhill's not George Kaplan and keeps devising creatively evil ways to get Kaplan killed: by a drunk driving "accident," by crop-duster, by falling from Mount Rushmore.
As much as he's smitten with Eve, he doesn't hesitate to take her out when the situation calls for it:
LEONARD: You're not taking her on that plane with you?
VANDAMM: Of course I am. Like our friends, I too believe in neatness, Leonard. This matter is best disposed of at a great height…over water.
After the narrow escape at Rushmore thanks to the state trooper shooting Leonard, Vandamm remarks:
VANDAMM: Rather unsporting, don't you think? Using real bullets…
Clearly, spying is somewhat of a game to him. A deadly game.
Vandamm's Timeline