Usually, whenever a marriage between two people falters, one can parcel out blame and responsibility in a fairly representative manner to both parties. I guess I am going to go against this and place much of the blame for the marriage's failure at Othello's door. I think that Othello's fears and insecurities ended up overtaking his own judgment and sense of trust. Rather than openly discuss his fear with her, Othello harbored them in his own subjective and then started to use them as a way to view Desdemona and her actions. Of course, all of this is triggered by Iago's treachery and had he not been so skilled in manipulating Othello, the marriage probably is saved. Yet, Othello's own insecurities regarding age, social status, ethnicity, and psychological sense of self all contribute to destabilizing him and his marriage for he is unable to understand and appreciate Desdemona's own authenticity and love for him. In this, the marriage fails.