What is the significance of Alfieri's character in Arthur Miller's "A View From The Bridge"?

"A View from the Bridge" is a tragic tale of an immigrant longshoreman who, through his obsessive love for his wife’s niece, destroys the very fabric of his world and in so doing, destroys his life. Alfieri’s role in the play is key to understanding not only the immigrant world of Eddie Carbone but also the inner struggles of the protagonist. Alfieri not only elevates Eddie’s status to that of a tragic hero in the play, but he also gives the audience a perspective of Carbone's suffering. Alfieri represents the metaphorical bridge between the immigrant slums, Red Hook, and the affluent world of the American dream, Manhattan. One of the key roles of Alfieri as narrator is to act as a chorus in a greek tragedy and so doing he raises the status of Eddie Carbone to that of a tragic hero whose fatal flaw brings about his downfall. He reminds us at every juncture that the course of this play will not run smoothly but like the chorus in the Greek tragedy, Alfieri is unable to alter the course of the action. His many warnings both structure the action of the play and raise the tempo. The narrative is set in the present, but Alfieri’s presence always reminds the audience that this is a story that has already happened and it is the uneasy alliance between the past and present that creates dramatic tension in the play.