Iago, the ensign to the African general Othello in the William Shakespeare play "Othello," is out for revenge, and he has good reason. Othello, commander of the Venetian Army, passed over him for the desirable rank of first lieutenant. Iago is furious that the prize went to "one Michael Cassio ... that never set a squadron on the field." In revenge, the ensign launches several plots, which he fires like arrows all over. The effects of Iago's manipulations range from stained reputations to ruined lives.

Peace of Mind Destroyed

The most obvious effect of Iago's manipulation is to destroy Othello's peace of mind. Iago hints that Othello's wife, Desdemona, has been unfaithful to him and Othello's mental state disintegrates quickly. Playwright Jerry L. Crawford notes that Othello begins as a great and noble creature who becomes a jealous beast as Iago suggests that Cassio, among others, has lain "with her, on her, what you will." Iago even gloats as he ends Othello's contented marital state, musing that "Not poppy nor mandragora ... shall ever medicine thee to ... sweet sleep."

Murder and Suicide

Although no proof of unfaithfulness exists, as Desdemona has not been unfaithful, Othello kills her to appease his now-insane sense of justice. Critic William Hazlitt reminds the reader that the responsibility for Desdemona's killing falls on Iago, a "philosopher who [finds merit in] a lie that kills." The murder has other effects, which tumble down on Othello like fallen dominoes: the general loses his reputation, his rank, his house and finally his life when he commits suicide.

Other Lives Ruined

Not content to simply destroy Othello's marriage, Iago ruins other lives. He falsely labels Cassio an adulterer by leaving Desdemona's handkerchief in Cassio's quarters. He then stabs Cassio in the dark and blames the innocent seamstress Bianca for the attack. Iago promises Roderigo, a foolish nobleman, Desdemona's love and then stabs Roderigo in the dark as well, leaving him to cry "O Iago, thou damn'd inhuman dog."

Self-Destruction

The final effect of Iago's manipulations might be the character's own fall into madness. Iago at the play's end experiences what Yale professor Harold Bloom calls a "sickening loss of being." Earlier in the play, Iago explains all his motives to the audience in his soliloquies, but he ultimately refuses to give any word of explanation to Othello, saying cryptically, "What you know, you know." Iago's manipulations have destroyed his own mind as much as they have destroyed others' lives.