This video pretty much explains why the U.S. and Iran can never reconcile their differences 100% at this point in time unless there are major policy changes by both sides:
https://www.youtube.com/watch?v=wiyCWKJPdUUIn reality, I can see Iran forming a military alliance with Russia and China that will serve as a check on the military alliance between the U.S. and its allies such as Israel, England, Canada, etc. An alliance between Iran, Russia and China might actually reduce the chances of war between the U.S. and Iran and encourage them to negotiate their differences on a more peaceful level. On the other hand, if war does break out between the U.S. and Iran, it will be much more devastating and could potentially go nuclear due to a possible alliance between Iran, Russia and China.