Hahaha! You're really a funny guy.
The American decision on that issue will solely depend on where America's strategic interests are according to the calculations of their strategic planners. But I think it will be reasonable to infer that "the" emphasis will be placed on what Iran will do with its nuclear program.
Nuclear program eh? What makes you think Iran is making bombs? Your people also said Iraq was making bombs, turned out to be a big lie. On the other hand, Israel already has nuclear bombs. However, your double standards blinds you from seeing that reality. Now you may cite the rhetoric from Iranian side against the Zionists being cause enough for an attack, but then again, where don't you find rhetoric?
Khruschev reportedly claimed, he'll "bury" Capitalism. Did he? Could he? Pakistanis claim to be capable of wiping out India day in and day out. Does that mean we go in whenever we wish and decimate them like we can? If you are so afraid of rhetoric, how can you live in life? What's next? War against Mother Nature cause she unleashed a hurricane on United States and is threatening it with another storm?
I find it hard to believe that "the most powerful nation" is also the most coward nation on Earth. Even countries like Vietnam and Cuba seem like macho men compared to America.