Levenson, Jill L. "'Alla Stoccado carries it away':
Codes of Violence in Romeo and Juliet." Shakespeare's Romeo and Juliet: Texts, Contexts, and Interpretation. Ed. Jay L. Halio. Newark: U of Delaware P, 1995. 83-96.

Thesis: Levenson reviews appearances of weapons, fights, and metaphors of violence in Romeo and Juliet, then provides an account the attitudes towards sword fighting conveyed in three dueling manuals, particularly Vincentio Saviolo's His Practise (1595). She focuses on the manuals' moral justifications for fighting, but says, "In the fight scenes of Romeo and Juliet this moralizing and its paradoxes, central to the dueling code, remain conspicuous by their virtual absence" (88). She concludes that Romeo and Juliet discredits all codes of violence:

Impelled by duels and fighting, Romeo and Juliet consistently deprecates them both. Three times it shows a visually striking match, a contradiction in styles of fence, ending in chaos or death. It follows the issuing of a challenge to its conclusion in two fatal duels and exile. Throughout it echoes instruction published by Saviolo -- from appropriate behavior at great feasts to strategies for avoiding conflict with a "friend" -- demonstrating over and over that it does not work.   (93-94)

An Interesting Sidelight: Levenson makes the point that despite what Saviolo says about the morality of fighting, it was often done just for fun:

Verisimilitude informs many aspects of the fight scenes in Romeo and Juliet, from the opening of the first scene. In light of the play's time scheme, Edelman's analysis of the well-known stage direction "Enter Sampson and Gregory, with swords and bucklers" shows the two servingmen making their way on a Sunday morning to a Veronese equivalent of Smithfield. They carry weapons appropriate to their status, prepared for any eventuality at the sort of place where Londoners met for fencing contests and the odd duel. According to the document that supports this interpretation, Edmund Howes's continuation of Stow's Annales, the bellicose pair spend their time in recreation both out of fashion with the upper classes and politically incorrect:
This field commonly called West Smithfield, was for many years called Ruffians hall, by reason it was the usuall place of Frayes and common fighting, during the time that Sword and Buckler were in use. . . . This generally embraced of vs all: whereas the good is vnwillnglye receiued, and we stoppe our eares least wee should heare of it. . . .
Saviolo argues that one should undertake combat only "for loue of vertue, and regarde of the vniuersall good and publique profite," and one should never become involved in the process of challenge without just cause or certainty of guiltlessness. Repeatedly he states that God distributes justice in duels, punishing those who may seem to have right on their side as well as those who display insolence, contumacy, or malice.   (87-88)

Bottom Line: Informative, but what Levenson says about Shakespeare's attitude towards violence is said better by Prince Escalus.