U.S. could use Iran's help in Syria. Iran is one of the main backers of Syria's current president who is at the core of the fighting in Syria. Iran has been invited to the international talks at Geneva and it is possible that Iran can help bring an end to the conflict in Syria if it proposes peace to Syria's president.
Whether or not they get Iran's help is a different story. The new regime in Iran seems to be much more reasonable than the old one. They were at least willing to try to work with the US on it's nuclear program, in order to get some of it's sanctions removed. The US might be able to work another deal with Iran to get the Syrian conflict resolved.
No, the U.S. cannot use Iran's help in Syria, because that is not a good way to make real change in Syria. Iran cannot be trusted, and we would not want them to get a hold of any of our arms, our strategies or technologies. The United States should work with its allies, not Iran.
I think we have stepped up so many toes abroad, its time we came back home. The country we live in just isn't the same as it was 20 years ago. We shouldn't be worrying about others problems, when we have so many of our own to get out of the way first. Syria is a whole other issue, let it be.
I do not think it would be a good idea for the United States of America to use Iran's help in regards to the situation in Syria. Iran has proven time and time again to be an enemy of the United States of America when it comes to diplomatic and foreign policies.