In the play "Romeo and Juliet", what is the dramatic contribution of the family feud to the love story of the play?it is relevant to the whole play.

As the Prologue explains, the entire plot is set against the "two households, both alike in dignity" that have a long feud against each other.  Had Romeo had another name as Juliet wishes, the young lovers may have been able to not have had such a "star-crossed" life.  Then, the play would not have been a tragedy.  So, in essence, the family enmity is absolutely intrinsic to the entire drama.