While negotiations between Europeans and Iran continue, it's all apparently for nothing. The Iranians go through the motions of negotiating, while insisting that they must have nuclear weapons, to assure Iranian power in the region, and as protection from American attack. Work on Iranian nuclear weapons continues, although European nations are making more of an effort to crack down on illegal exports of industrial equipment to Iran.
The Iranians now threaten to cut off oil exports from the Persian Gulf by mining the narrow Straits of Hormuz, and placing their anti-ship missiles there as well. The Iranians are quite confident that they could close the Straits. American and allied navies believe they could shut down Iranian attempts to block the Straits, but they only way to find out who is correct is for the Iranians to try it. No one looks forward to that.
As long as Iran is controlled by a religious dictatorship, the situation is not going to change. There are no signs of an impending revolution in Iran, and the religious government would welcome an attack by the U.S., as this would whip up a patriotic fervor among even anti-government Iranians.