Would you be able to kill a person?

In a situation where a potential victim is armed, one can commit murder without hesitation. At least, the instinct for self-preservation might push one to do so. Here, almost everyone finds themselves in the same situation... But when you have to look into the eyes of a helpless person, see their pleading gaze, and realize that they are essentially innocent and don't deserve to die... Even if you know that they are the worst kind of person, it's very, very difficult to kill them, I think. Not everyone can do it. I wouldn't be able to. And even if I could, I would definitely regret it afterward; I would be haunted by the thought that there might have been another way to resolve the issue or problem... No, tell me, could you drown a puppy? I probably wouldn't be able to do that either.