The person who is most at fault in the book "Romeo and Juliet", is Romeo. Romeo was the one who caused all the disasters. He knew he shouldn't been with Juliet because she was a capulet, who was the enemy of his family. Also Romeo falls in love with girls to quick, he was just in love with Rosaline. That affected him and Juliet because he fell in love with her too, to fast, an example when he said to Juliet  "If I profane with my unworthiest hand. This holy shrine, the gentle fine is this: My lips, two blushing pilgrims, ready stand. To smooth that rough touch with a tender kiss." that's when things went downhill. You shouldn't date the daughter of your enemy and you shouldnt fall in love with a girl you just met. If Romeo had follow these rules every one in the beginning of the play would still be alive at the end.