I know someone has already posted but the point of Michael taking out Fredo is to show how despicable he has become, cruel, selfish, paranoid beyond belief and mad with power. This is the final nail in the coffin and should have ended the saga....bring him back in Godfather Part III and trying to get us to root for him was massive mistake and one of the major reasons I dislike that film.
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"Frankly, my dear, I don't give a damn"
"I need your clothes, your boots and your motorcycle"
"Frankly, my dear, I don't give a damn"
"I need your clothes, your boots and your motorcycle"