In Othello, Iago is extremely manipulative. Iago is a master at manipulation. Through his mere words, he plants seeds of doubt in Othello. Truly, Iago is subtle in his accusation as he merely suggests that Cassio may be having an affair with Desdemona. No doubt, Iago manipulates the situation to convince Othello that his wife is unfaithful with Cassio. When Cassio and Desdemona are merely talking, Iago leads Othello to the scene. As Othello views the scene, Iago plants seeds of doubt and jealousy in Othello. He uses hesitation as he speaks. This causes Othello to question what Iago is really saying. With Othello's insistence, Iago gives in and expresses his dislike of Cassio and Desdemona talking to one another:
Ha! I don’t like that.
When Othello questions Iago in saying, "What did you say?" Iago begins scheming. Iago pretends to be hesitant in his accusations:
Nothing, my lord.
Artfully and cleverly, Iago is causing Othello to think that Cassio and his wife should not be talking.
When Cassio realizes that Othello is coming, he quickly leaves the scene. Iago uses this moment to make Othello think that Cassio is stealing away because he is guilty of having an intimate talk with Othello's wife. Iago comments about Cassio quickly fleeing from the scene:
I cannot believe
That he would steal away so guiltily,
Seeing you coming.
Later on, Iago uses Cassio's genuine support of Othello to tempt Cassio to become intoxicated, thus causing him to brawl with Roderigo. Of course, Iago is a master manipulator:
Come, lieutenant, I have
a bottle of wine; and here outside are a number of
Cyprus gents that would happily drink a round to the
health of black Othello.
Although Cassio initially refuses to drink, Iago uses his gift of scheming and talks Cassio into getting drunk.
After setting the scene, Iago moves on to further his evil plot. After Cassio and Roderigo fight, Othello releases Cassio from his position as lieutenant. Iago furthers his devious plan by manipulating Desdemona. Using Desdemona's prime weakness, naivety, Iago puts Cassio up to seeking Desdemona's help in getting his position as lieutenant back.
With the scene set, Othello begins to believe his beautiful Desdemona has been unfaithful with Cassio. Iago realizes Othello's insecurities and benefits by them. Othello is too trusting of Iago. Iago ever so subtly points out that Desdemona is capable of lying:
She deceived her father by marrying you;
Iago is a crafty manipulator. He definitely causes Othello to question Desdemona's integrity. At the same time, Iago assures Othello that he has only discredited Desdemona because of his love for Othello:
I hope you will consider that what I have spoken
Comes from my love;
Iago craftily apologizes for loving Othello too much:
I humbly beg your pardon
Because I was loving you too much.
Convinced of Iago's love, Othello states that he is forever indebted to Iago:
I am bound to you forever.
No doubt, Iago is a master at deceit. Iago is an excellent actor. He is convincing in his false sincerity. Because of Iago's expert manipulation, Othello smothers his beautiful wife.
Iago's ability to read a persons character allows him to find the flaws in each of his victims ...especially Othello , who opened himself to Iago's plotting and scheming.
He creates an impression of honesty and truth only to win Othello over and the be trusted wholeheartedly by the General. Iago learns of Othello's weakness, being his wife Desdemona, and uses this to plant doubt that leads to anger and hatred to the point of murder.
Iago draws Othello in by pretending in his presence to be true to the Moor and by so doing, gains Othello's trust. He 'implies' to Othello what he learns in the hope that Othello falls for his deceit. He wins by convincing Othello of his loyalty and the fact that he wishes not to 'cause doubt', yet that was his sole purpose. Othello buys into the pretense and allows Iago to manipulate his thoughts against his wife Desdemona.
He cleverly sets both Desdemona and Cassio up for the bait, and Othello being so trusting , sees into this eluding as a betrayal by his adored wife with his newly promoted lieutenant.
The rest is left to Othello to 'find out' and come to a conclusion about. and all Iago does is sit back and watch the ball in play as the anger envelopes Othello and his hatred over powers the otherwise calm and calculated general he is...