I doubt an attack on the games will happen as the conspiracy theories surrounding this have been mentioned on radio, tv and the newspapers, so if anything were to happen much of the public would then sit up and think that the conspiracy theorist were right after all and start looking for answers which would be far to risky for the powers that be.
Not only that but the security surrounding the games is massive so if anything was going to happen my guess is that it will be somewhere else while we are all focused on the games, the just imagine the drama and the sympathy they could show during the games for the country which is the victim while everyone falls in line behind the flag waving as Iran is attacked in revenge!