I understand that the intention is to disable and not kill. However, if there is a person with a knife taking an agressive posture toward you THEIR intention is to KILL not DISABLE. If they only wanted to fight, the knife would have never come out. If they didn't want a confrontation to begin with, they would have just left. My point was that if you are in that situation, you are in a better postion if you have a superior weapon. There is a 3 prong test for deadly force in law enforcemnt. That test is method, threat, and opportunity. If you meet all three prongs, you should not be going hands on, you should be shooting!