From
http://www.reuters.com/article/2011/11/18/us-usa-iran-economy-idUSTRE7AH02O20111118">Reuters:
(Reuters) - U.S. Defense Secretary Leon Panetta said he would raise American concerns about the unintended consequences of any military action against Iran during talks with his Israeli counterpart on Friday, including its potential impact on the world economy.
--snip--
"And I have to tell you, thirdly, there are going to be economic consequences to that, that could impact not just on our economy but the world economy," Panetta said.
"So those things all need to be considered."
Panetta is due to attend a security forum in Halifax, Canada, where he will also hold bilateral talks with Israeli Defense Minister Ehud Barak on Friday.
Much more at the link!
It's the assumption that the US doesn't feel it would necessarily be given warning in an unprovoked attack by Israel on Iran or that the US would be contacted only once the Israeli fighter planes/missiles/etc. were already on their way. It's much more common for the US to keep these kind of speculatory reservations out of the press.
And earlier this evening,
http://www.jpost.com/IranianThreat/News/Article.aspx?ID=246028&R=R1">Israel watches as world rejects Iran sanctions.
Tick-tock.
PB