Does he see Iran as a serious threat to America without regards to the former Soviet Union? He seemed to ignore that other than to say that if they tried anything, "they wouldn't stand a chance". That does not mean that are not a serious threat. Remember, they tried something on November 4, 1979. Not only did they stand a chance, they succeeded in their goal. Who was behind the takeover of the US Embassy? The President of Iran.
No one is saying not to talk to Iran. The only way we will have peace with radicals like Iran, is to make sure they know the consequences of an attack are known and will be severe. If they attack one of our allies, the consequences will be severe. It has to be clear what the outcome will be.
The difference between Iran and the former Soviet Union is that Iran believes "that they have been sent by Allah to destroy America. They believe they have been chosen by Allah to rid the world of Israel and America and they will be victorious. Do you think they care about how much we spend on defense? To them, that does not matter. They are seeing this from a religious point of view.
What is going to happen if and/or when Iran attacks Israel? With the anti-war crowd doing what they do best, does Iran think we are going to be quick to react? Do they think we will be serious in our response? Or do they think that "Cut and Run" mentality will prevail. It does not matter what the reality is, but what Iran perceives.