I believe that the United States must take a clear and firm stance against Iran, I believe the United States needs to make it absolutely clear that developing nuclear weapons is unacceptable and attacking Israel would bring the United States immediately in to aid it's ally in military and economic ways.
The U.S should take a harder stance on Iran, especially since Iran is threatening our allies Israel in the middle east. The last thing we need is for a war to break out in the middle east, or for Iran to complete a nuclear weapon. As it currently unfolds, Iran is closer than every to accomplishing just that. With Americans taking a more hardline stance and imposing sanctions, Iran will be forced to stop their nuclear ambitions.
Israel has the world's largest stockpile of nuclear weapons in the world. If anything, it is Israel who would attack first. Ayatollah Khamenei said that carrying nuclear weapons were a sin. Plus, hypothetically, why couldn't Iran have nuclear energy? The U.S. was the only country in the world to use a nuke- and they used it twice!
If the United Stated complies with the policies of Iran, it may hold back whatever goals they have, but forcing compliance to demands may only endanger the image of the United States to many countries - this is the center of much conflict between the two parties in the first place.
No, the U.S. should not take more of a hardline stance on Iran, because so far they haven't attacked us. Most of the 9/11 attackers were from Saudi Arabia and trained in Afghanistan. Iran might not have had a problem with it, but they are not threats themselves. We should treat them like a cold war until they provoke us.
When their previous president was in office, I was all for a more hardline approach. I do not like crippling sanctions, but was actually supportive of them when it came to Iran. Things seem to be changing for the better in Iran now, though, so I think the US should step aside.