By making Juliet marry Paris, who she did not love, Capulet also separated her from Romeo, who she did love and it was this separation that led to her downfall. This contributed to her death because her life wasn't worth living if she couldn't have the only person she loved, and he was the person she lived for. Therefore Lord Capulet is partially to blame for the tragedy due to his inconsideration of his daughter's opinions and feelings.
