Iago the "Green - Eyed Monster"
Iago did nothing but instigate Othello’s jealousy towards Michael Cassio and Desdemona. Initially, Iago had just told rumors to Othello; still giving Othello hope that Desdemona was faithful to him. However that wasn’t enough for Iago, for he had acted upon Othello’s jealousy by stealing the handkerchief and giving it to Cassio. According to Watson, the handkerchief represented Othello’s love, and commitment to Desdemona; but overall it symbolized betrayal in the end. The handkerchief was the first gift Othello had given to Desdemona, making it the equivalence to a wedding ring, and it brought hope that they would stay together for the rest of their lives, as said in "Othello Reformation Tragedy."
When Othello saw the handkerchief in the hands of Michael Cassio, he was more than convinced that his wife had betrayed him. Knowing it was in the hands of another man made Othello think that the handkerchief and Desdemona had been contaminated, as presented by Nordlund. If the handkerchief was supposed to represent their love and virginity, why would Desdemona give it away thought Othello, as said in The Norton Shakespeare (page 2109). Nevertheless, Othello’s jealousy didn’t get in the way of his actions,