This is a very pertinent question to ask about this excellent play. Certainly there is ample evidence in the text to suggest that Nora's situation is the result of more than one person and society. A key part to analyse closely is the end of the play, when Helmer and Nora have their final showdown. Nora is able to be completely honest with her husband and is able to express how she was treated both by her father and then by her husband:
When I lived with Papa, he used to tell me what he thought about everything, so that I never had any opinions but his. And if I did have any of my own, I kept them quiet, because he wouldn't have liked them... then I passed from Papa's hands into yours. You arranged everything the way you wanted it, so that I simply took over your taste in everything...
Thus we can say that Nora's plight is the result of the way she has been treated by her father and then the way that her husband treated her in exactly the same way. This has resulted in Nora being married to a complete "stranger" and has never been able to achieve independence herself, because her father and then her husband have always protected her from the world because she was supposedly so "weak and fragile."
However, it would be unfair to lay all the blame at the feet of Nora's father and Helmer. Ibsen equally blames society for the way that it treats women as fragile objects or possessions that men need to dominate and protect. Ibsen seems to be suggesting that we do society at large a profound disservice by treating them this way and that women need to be recognised as human beings rather than just another possession, like the "doll" that Nora identifies herself with.