What the theme of jealousy in the play, Othello?

Traditionally, Othello was read as a cautionary tale about the destructive nature of the green-eyed monster, jealousy. Certainly, the play is filled with examples of jealousy, each contributing to the claustrophobic atmosphere of plot and counterplot, all orchestrated by Iago. Iago himself attributes his hatred of Othello to numerous sorts of jealousy: he is jealous of Michael Cassio because he believes that Cassio has been promoted unjustly over him and because he believes that Cassio might have had an affair with his wife. Iago is jealous of Othello because he believes that Othello might have had sex with his wife and because he says that he loves Desdemona himself. It is almost as if Iago examines the various kinds of jealousy he finds in himself in order to exploit those jealousies in others. For example, he first manipulates Roderigo. Roderigo, in love with Desdemona, is very jealous of Othello and by extension of Cassio. His jealousy makes him an easy dupe for Iago's plotting. Likewise, Bianca is jealous of any woman in whom Cassio might be interested, and thus she also can be manipulated by Iago. Of course, the most destructive jealous rage that Iago incites is that within Othello. Iago uses his own fear of cuckoldry as the basis for his plot against Othello. By projecting his own feelings (and a common cultural fear) onto Othello, he is able to convince Othello that what he fears most, Desdemona's betrayal, is a reality. It is jealousy that weakens Othello's mind and reason, thus rendering him increasingly vulnerable to Iago's plots.