The reason for Iago's success is his ability to manipulate both the strengths and weaknesses of his enemies

The reason for Iago's success is his ability to manipulate both the strengths and weaknesses of his enemies this is shown through Desdemona when he uses her kind nature against her to convince Othello that she is cheating on him with Cassio, as she tries to help Cassio, get his position back, he also manipulates his own wife Emelia to steal Desdemona’s handkerchief, and she does to please him.