Many people have hit upon the limitations of the knife, now let me touch upon the limitations of the movie. DON'T see it. I am a very forgiving movie watcher, and usually am able to come up with some redeeming quality that a movie has. This has none. Despite the pedigree of its performers, the performances were laughable. They looked as though they realized how bad the movie was and were just trying to get it over with.
The military 'tactics' at the beginning were written by somebody's twelve year old, and let me give you an example of the dialogue:
FBI Agent: "Why were you killing these people?"
Captured Killer: "Did you know 30 million chickens are killed every year?
FBI Agent(impressed): "No I didn't, but it's interesting..."
*embarassed pause*
That's right folks, PETA (or someone) got ahold of the script and threw this and other gems into the mix. My favorite was when our Tracker hero tracks down a wolf that was hurt in a trap, walks up to injured, bleeding wolf, pulls the trap wire from its leg, and then the wolf licks him in thanks. I still have scars on my hand from trying to pull a sticker out of my dog's foot.
The only part of the movie that was supposed to be done well was the authenticity of the knife fights. Well, all the moves were authentic. Only problem is, all of them were killing moves, and our combatants keep jumping up and shrugging them off. Reminded me of the Black Knight from Monty Python, but that was supposed to be goofy.
This was the first time I ever walked out of a theater and couldn't say, "Well, at least _______" Save your money, friends.