Reputation Damaged: Cassio's drunken behavior tarnishes his reputation as a responsible and capable officer. Iago manipulates the situation to make it appear that Cassio is unfit for his position and unworthy of Othello's trust.
Loss of Position: Due to his drunken misconduct, Cassio is stripped of his rank as lieutenant by Othello. This demotion not only affects his career but also adds to his humiliation and distress.
Manipulation by Iago: Iago exploits Cassio's intoxicated state to further his own malicious plans. He convinces Cassio to start a brawl, which disrupts the peace in Cyprus and provides an opportunity for Iago to sow seeds of doubt about Cassio's loyalty to Othello.
Increased Tension and Conflict: The consequences of Cassio's drunkenness add to the rising tension and conflict within the play. It fuels Othello's suspicions of Desdemona's infidelity, leading him down a destructive path of jealousy and irrationality.
Catalyst for the Tragic Events: Cassio's drunken actions set in motion a chain of events that ultimately culminate in the tragic downfall of Othello, Desdemona, and Cassio himself.
In essence, Cassio's drunkenness serves as a catalyst for the play's tragic events, underscoring the destructive consequences of excessive drinking and the ease with which others can manipulate such situations for their own nefarious purposes.