This USA Today/Gallup poll probably sums up attitudes of the American public toward Iran pretty well:
A new USA Today/Gallup poll finds most U.S. citizens don’t think the United Nations can solve the growing Iranian nuclear dispute.
Pollsters … found only five percent of U.S. citizens are “very” confident in the United Nations, 28 percent “somewhat” confident and 67 percent either “not too” or “not at all” confident the international body will resolve the nuclear standoff.
Fifty-seven percent of those polled said they opposed U.S. military action against Iran if it doesn’t end its nuclear program.
Thirty-six percent did support such action and 6 percent didn’t have an opinion.
So pretty much everyone recognizes that the U.N. won’t do anything, but most don’t want us to do anything, either. Hoping for the best is not a policy, and the administration, unlike poll respondents, has to have a policy.