I understand what you're saying,
@Ranger715 , but in the language, reasonable and necessary are intertwined in this context - it's typically "reasonable force that's necessary to protect oneself (and/or one's property, depending on locale)."
So then the question arises, logically....
The issue here is whether a lethal response is reasonable and necessary - and given that the threat presented is a lethal one (i.e. assuming that AOJP is met - that it's not a toddler dressed up as Jason from
Friday the 13th and armed with a paring knife, coming at me, a 6', 250" able-bodied man), the proportionate response of lethal force is logically reasonable and necessary.
It's not about two equally sized and aged men duking it out in
Fight Club nor the recruitment of a champion for Trial by Combat.
Lethal force is by-definition lethal, and it does not matter if that is achieved via a gun, a knife, or a motor vehicle (it's interesting and informative to look up various institutional Use of Force policies towards this).....or via bare hands/feet.
It's about understanding the legal requirements of the use of force in self-defense, so that we not only prevail in the dire encounter, but also survive the legal and civil quagmire that may well unjustly follow due to politically motivated prosecution and vengeful parties who cares not who was the true victim of a crime or who was actually in the right.
The legal principles of AOJP (detailed in the author's "What is Considered Self Defense?" section) and "proportionality of response" are areas that every person looking to exercise their right of self-defense - armed or otherwise - should be familiar with, as we've now seen well-publicized trials where those involved have been properly acquitted under the law (Zimmerman and Rittenhouse, to name the two most well known)...and we also know well of cases where the rightful defender whose action abridged these considerations, and have ended in tragedy (Claude Werner's
Tactical Professor blog routinely tracks "Bad Outcome" instances).