Regarding Shakespeare's Romeo and Juliet, and Escalus' responsibilities, if I were to write a persuasive essay on this topic, I think that I would discuss the sense that this has been going on a long time—much too long for a Prince not to do something constructive.
Escalus should have done something sooner because the feud has been going on for so long that no one even knows what the original fight was about—and still Escalus done nothing.
I would include comments from the beginning (Act I, scene i) that show how pervasive the hatred is, which must be obvious even to Escalus: it's not just that the families are fighting, but it has reached down to the servants who are willing to kill each other for the sake of the family. (I don't think I could be paid enough money in any job to put my life in jeopardy for the sake of my boss and his personal problems: this simply shows the obsessive trend that has permeated all levels of their society.)
Another situation that points to how out of control the situation is can be seen (in Act III, scene i) when Tybalt kills Romeo's friend, Mercutio. Being related to the Escalus himself, I would have thought this would have been the last straw for the Prince. Just because Mercutio is a friend to a Montague does not constitute reason for his death at Tybalt's hand. And even though Tybalt is after Romeo for disrespecting the Capulets by attending their party, he reaches past Romeo to kill Mercutio—other than emotionally hurting Romeo, it would make no sense, except that Tybalt is a hot-head. And in doing this, Tybalt has lashed out at Escalus, not just Romeo. This should have been the wake-up call Escalus needed.
In essence, when looking for blame, is it not possible to find Escalus at fault? If he, as their ruler, is interested in protecting his people as a father would protect his children, shouldn't he have taken steps prior to Romeo's banishment, rather than waiting for tragedy to take place? Based on the depth of this problem within the society, it was inevitable that something truly tragic would ultimately take place. Escalus should have been more concerned and more forward-thinking.
Are you trying to get arguments to support this statement or refute it, or just a general discussion of the issues it raises?
I think one of the major issues that needs to be considered is how plausible it is for anyone to "end" a feud just like that. Even when the Prince declares the edict of no more bloodshed, that does not work, and instead resentments are buried and harboured perhaps even more than if they could be expressed openly. Notice that the chorus tells us that the conflict we witness between the Capulets and the Montagues, although perhaps is a new manifestation, stems from an "ancient grudge." Laws by themselves don't just change people's emnities overnight.
Secondly, being very Machiavellian and cynical, it may be to the Prince's advantage to have this feud going on. There is a phrase that comes to mind: divide and conquer. It may suit the Prince's interests to have two key noble families so caught up in their feud with each other that they do not try to oppose him. There is no evidence to support this in the text, but it is an idea worth thinking about.
Hope this gives you a few ideas to play with. It is an interesting essay title!
While background information on the length of the reign of Prince Escalus in Romeo and Juliet is not available, it is difficult to assign a great deal of responsiblity to the prince for the ending of the feud. For one thing, in the Prologue of Act I, the Chorus states, "From ancient grudge break to new mutiny...," a statement which seems to indicate that the feud, while yet existant, has been no cause of civil unrest until recently. So, the Prince, being a politico as all rulers are and have ever been, would not wish to broach the subject of ending a feud at a time when it is dormant. Rather, he would do as the old cliche, and "let sleeping dogs lie." After all, in his address to the citizens, he mentions how the swords of Capulet and of Montague are rusted from not having been used (l.91).
Now in Act I when the feud "breaks out to new mutiny," Prince Escalus, angered at the "three civil brawls," declares,
If ever you disturb our streets again,
Your lives shall pay the forfeit of the peace. (1.1.93-94)
After making this declaration, the prince naturally assumes that he will be obeyed. So, his threat of death to any who disobey should be the end to the feuding, at least for the prince's generation, which is all he is probably concerned with again as a politico. Evidence of the prince's being a politico is provided when the prince learns that Tybalt has killed his cousin Mercutio because he banishes Romeo rather than having him put to death as he has decreed. Unfortunately, the prince does not realize that even more bloodshed will occur: the deaths of Romeo and Juliet themselves.