As suggested a few days ago, direct confrontation between the US and Iran is unlikely. Instead, we are likely to see acts that are viewed by the other as state sponsored terrorism, as evidenced by the third, recent, assignation of an Iranian nuclear scientist.
While oil prices go up because Iran is making its ususal empty threats, the world is peacefully oblivious to the real threat that is emerging - bio weapons. If Iran really wants to harm the US it could send over a form of weaponized SARS anonymously. Seasons greetings from the ghost of Christmas past, Michael Chrichton.