In the commentary on the home release of the last season of Game of Thrones, the actor addressed his character’s reasoning in that key scene.
The most devastating moment in the final episode of Game of Thrones came when Jon Snow entered the now destroyed Iron Throne room and killed Daenerys Targaryen. That scene, which to this day makes fans of the Mother of the Dragons furious, was probably something that had been anticipated since the moment Khaleesi set ablaze King’s Landing. However, the way the scene was developed was enough to leave every follower of the series baffled.
As you will remember, after passing through where Drogon was resting, Jon Snow met Daenerys in the Iron Throne room. The Mother of Dragons told him about her ambitions for Westeros now that she was finally the monarch. Snow reaffirmed that she was his queen, kissed her and suddenly stabbed her ending her life.
As expressed by Kit Harington in the commentary included in the Blu-ray of the last season of Game of Thrones (via EW), Jon Snow had not gone to see Daenerys with the intention of killing her, but after learning what Khaleesi was planning and her new moral views, convinced him to make that decision.
“He doesn’t know he’s going to betray her until right at the end,” he said. “In Jon’s head, it’s a number of [reasons: Dany] doesn’t factor in anyone else’s decisions and it also means [Dany] is going to kill my sisters, so it becomes [my] family vs. her.”
Although technically Daenerys is also familiar with Jon, Harington’s words suggest that the attitude Khaleesi had shown in the last episodes of the series was a danger to Westeros and in particular to Sansa and Arya. Well, after some quick Jon Snow reasoning, it was best to stop her at that moment before she continued with her plan.
