What is Iago's primary motivation for his actions in "Othello"?

Iago's primary motivation in "Othello" stems from jealousy and a desire for revenge. This complex emotion is rooted in his feelings of betrayal and resentment towards Othello, who he believes has wronged him by promoting Cassio over him. Iago's jealousy intensifies when he suspects that Othello has been involved with his wife, Emilia. This combination of jealousy and the longing for vengeance drives Iago to manipulate those around him, ultimately leading to the tragic downfall of several characters, including Othello himself. His actions are systematically calculated, showcasing a deep-seated desire to ruin Othello's life as payback, solidifying the role of jealousy and revenge as central themes in the play.