Obama is President of the United States. Netanyahu is not and the presumption that he can dictate US policy is just that, presumptuous. An attack on Iran was not in the US interest when Bush was President. An attack on Iran now is not in the US interest. World War III is not in the interest of the US right now.
One student killed, three wounded at Arizona campus during fight (a)
from the article: World powers urge Iran to accept standing nuclear offer