I was just thinking how interesting it is that people say that the theme of the play is "jealousy", though most references to "jealousy" in Othello do not refer to what we today think of as "jealousy".
Even the supposed defining moment when Iago tells Othello "beware, my Lord, of jealousy", Iago means suspicion.
Jealousy is used meaning 'suspicion' throughout the Shakespeare canon, such as in Julius Caeser: "That you do love me, I am nothing jealous".
Nice point, and believe you've hit the nail on the head here. 'Suspicion', rather than jealousy, is truly the crux of this play -- not only Othello's ready suspicions about Desdemona's faithfulness, but also the character's distrust of his own worthiness. He suspects that he is not worthy of such a love and such a lover.
The deepest suspicion one may find, however, is that of the audience's total and complete distrust of Iago's motives. He's Shakespeare's most evil bad guy, in that he really has no good motive for ruining Othello's life. Sure, say what you want about his petty thirst for higher officership or his bland and somewhat unbelievable insinuations regarding the faithfulness of his own wife. Nope, Iago does what he does for no real good reason at all -- and the crowning irony (another motif in this play) is that the little rat bastard is constantly being referred to as 'honest'! Branagh's portrayal is genius...genius, mostly because for the first time, I have a sneaking suspicion that Iago did it out of simple jealousy -- his own jealousy of anyone who might be more beloved of Othello than himself. C'est vrai?