Iran people and USA people are friend. why there is quarrel between Governments?

I do not believe that Americans are friends with Iranians. Many of us remember what Iran did to the US citizens during the Carter administration. The current president of Iran was one of the terrorists who were involved in this crime. It seems that many Iranians are afraid that Iran will be attacked by the USA. I do not believe that this will occur unless America is provoked in Iraq or elsewhere by Iran.