Iran is not a threat to the USA? Iranians have been killing members of the US military for years.
For the non-believers...
U.S. military leader says Iranian weapons killing Americans in Iraq - CNN
Iranian Weapons 'Killing Our Troops' in Iraq, U.S. Says
Iran Killing American Troops in Iraq and Afghanistan - Jeffrey Goldberg - International - The Atlantic
"We're not talking about a smoking pistol. There is no doubt this is Iranian," Jeffrey said in an interview.
"We're seeing more lethal weapons, more accurate weapons, more longer-range weapons," Jeffrey added. "And we're seeing more sophisticated mobile and other deployment options, and we're seeing better-trained people."
What does this mean? It means that Iran is waging war against the United States of America. Or, to put it another way, it means that Iran doesn't seem particularly interested in entering into a dialogue with the Obama Administration at the moment. Unless, of course, this is just a cry for help.