Sakura, in her mind, was out of alternatives to save Sasuke. She concluded that any other option but to kill him would endanger Naruto too much (bad ending), and since she valued Naruto's safety as a priority she resigned herself to the kill option.
Actually, I think it's a lot more complicated than that. What Sakura concluded was that Shikamaru meant what he said -- that the others were going to take action to kill Sasuke to prevent a war -- and she, as well as everyone else, had been relying on Naruto too much to resolve the issue of Sasuke on his own.
Sakura felt compelled to act on the Team 7 dynamic issues before the village could move to end Sasuke's life -- which included acting to protect Naruto, to release him from his promise to her regarding Sasuke, and to take responsibility for killing Sasuke.
The suggestion that she loved Sasuke so much she was willing to kill him to prevent his sinking any lower was speculation by Sai. And it is speculation that lacks evidence and substantiation.
Following the progression of events, Sakura finds out Naruto is in love with her and that her expectation that he will deliver on his promise to bring Sasuke back was hurting Naruto as much as Sasuke's defection. Shikamaru then confirms that Sasuke has earned death for his crimes, and he wanted permission from her and Naruto to take Sasuke out.
The implication there is that Team 7 should have the first shot at killing Sasuke because he is their own. Since Sakura knew Naruto would never do it, it was up to her.
Somehow, Sai took that to mean that she accepted the responsibility of killing Sasuke because she loved him enough to kill him, when it would essentially be an honor killing by one of his teammates. I don't think Sai understood the distinction.
Killing someone you care for to prevent them from becoming even more of a monster has been done in fiction too many times. It's an overused trope.
For what it's worth, BakeNeko-Chan made it clear she understood the trope, but was not talking about the trope. She was saying that regardless of how often it is used in fiction, it makes no sense to her personally. She cannot put herself in that position and ever imagine choosing that option no matter what the circumstances.
Honor killings exist in the modern world -- as a real life trope -- but that doesn't make such an ideological option any easier to understand if you're not from that culture. Same with the ninja culture choosing to hunt Sasuke down and kill him rather than let him rot in jail. The concept of Sasuke's death at the hands of one of his teammates being a preferred resolution is difficult to understand as an option of love and honor.
Just because a trope is common or overused doesn't mean it makes sense, or that it isn't used as a contrivance to generate angst. Fiction is fiction, and a lot of things that happen in fiction are accepted and yet still nonsensical to those of us rooted in real life.
Edited by KnS, 26 February 2014 - 05:12 AM.
