Christopher Nolan's movie has a devastating ending. Is it enough?

In Christopher Nolan's Oppenheimer, Gen. Leslie Groves (Matt Damon), yells that the Manhattan Project is "the most important fucking thing to happen in the history of the world!" Many historical dramas feel that way about their subjects, but most don't come right out and say it. Nolan's movie attempts to back that sentiment up, though, by dramatizing the fears and guilt the bomb inspired in J. Robert Oppenheimer (Cillian Murphy) in the post-war years. But does it matter that Oppenheimer felt guilty? Was Oppenheimer, as Nolan is telling the press now, hopelessly naà¯ve? And is Oppenheimer, the movie, telling the…