Iago is Othello’s ensign; also he is the villain of the play. He betrays almost everyone. The fundamental reason is Othello’s promotion of Cassio to the post of lieutenant, who with no experience had been leading men in battle. Therefore, Iago makes a terrible plan and he is going to take revenge on everyone-Othello, Desdemona, Cassio, Roderigo and even Emilia, his wife.
At the beginning of the play, Iago talks to Roderigo that he hates Othello because of his promotion of Cassio to the post of lieutenant. In spite of “three great men in the city” recommending him that Iago is upon Cassio for the position, Othello still chooses to give the position to a man with no experience. He is angry and he says “there are others/ who putting on a good show of duty/ are really looking put for their own interest” (1,1 50-52). This quote demonstrates that Iago waits for an opportunity to give revenge; he only pretends to serve Othello. Furthermore, Iago lies to Othello that Cassio has told him he has lain with Desdemona in order to infuriate Othello. As he says, “my medicine, keep working! This is how gullible fools are caught/ and how many worthy and chaste women/ all guiltless, wind up accused” (4, 1 51-54). Obviously, he betrays Othello.
In Act 5, after Desdemona dies, Othello talks to Emilia saying that Iago has found Desdemona’s falsehood. Emilia is anguished and she says, “Oh, my lady, a villain has toyed with your love/ My husband said she was unfaithful” (5, 2 181-182). As we all know, Desdemona is loyal to Othello. She puts her marriage into high position of her life. However, Iago forges lies of Othello which caused Desdemona to be misunderstood by Othello who thinks that she is having an affair with Cassio. Thus, Iago betrays Desdemona.
Cassio is a young and inexperienced soldier, whose high position is much resented by Iago. Iago is smart and he is good at understanding and manipulating others. He knows Cassio’s weakness when he says “if I can get him to drink just one more cup/ on top of what he’s had to drink tonight already/ he’ll be as quarrelsome and disagreeable/ as my young lady’s dog” (2, 3 43-46). Iago leads Cassio into committing an action that will disgrace him. Consequently, Iago betrays Cassio.
Roderigo loves Desdemona, and he gives all of his money to Iago because Iago promises him he will help Roderigo win Desdemona’s heart. However, Iago uses all the money for himself; Roderigo is just a tool to help him accomplish his revenge. When Iago’s plan is nearly complete, he thinks about “ if Roderigo lives/ he’ll expect me to give back all the gold and jewels I swindled him out of/ as gifts to Desdemona/ That must not happen” (5, 1 14-17). This demonstrates that he is about to kill Roderigo. Afterward, he stabs Roderigo without hesitation, and he pushes all the charges on him. Hence Iago betrays Roderigo.
Emilia is Iago’s wife, but Iago doesn’t care about her. Emilia is just another tool. He asks Emilia to steal Desdemona’s handkerchief. At the end of the play, when Emilia accuses Iago of villainy, Iago no longer certain he can keep his trick hidden so he stabs Emilia in the commotion. Therefore, Iago betrays Emilia.