In Othello, most men in the play are warriors. They have been surrounded by the beastly and uncomprising atmosphere for a while. The play's events actually play out like a battle. Iago resembles a force that is coniving and pure evil, but appears good-hearted and wise. All of the characters become entranced by Iago's foul words and fight among themselves. Iago is an evil diplomat that plays "countries"' strengths against each other.
The warlike atmosphere creates more tension and stress than a calming environment would. This environment allows for Iago's lies and deceptions to hold more weight. Iago is thought to be wise, so he is trusted to be the most knowing on matters. Othello has duties that he must attend to, which allows for Iago to infiltrate Othello's thoughts with adultrey.