You can legally attack someone, in any state, just because you feel threatened by her, even if she didn’t do anything to you?
Well, as I noted above, it is an objective standard that a reasonable person would have to feel threatened.
Why does that surprise you?
Imagine a guy comes to you with a gun and aims it at you, and says he will kill you. But has done nothing to you. Shouldn’t you be allowed to shoot him first?