I don't see a war coming as Iran is not Iraq and the United States knows that.
Under the United Nations sanction, Iraq was striped down to it's bones. Every single detail was known about what they have and where it's at. They wanted to invade in-order to secure oil supply and have presence in the region.
Iran on the other hand is a very different kettle of fish. It has the largest army in the region, highly motivated (they total support the government on the nuclear issue) and is armed to the teeth. Keep in mind that the population of Iran stands at 70 million and 60% of that is below the age of 30.
If there is an attack, it will destabilize the region and America will come out of this with a bloody noise and many body bags. There will be no winners and everyone will pay for the United States lack of diplomacy and arrogance in this matter.
I therefore don't see this escalating to a war, but rather a war of words. I hope that both sides will come to their senses and resolve this peacefully.