With Mahmoud Ahmadinejad demanding apologies from the U.S. for its historical behavior towards Iran, Steve Rosen notes that the Clinton administration more or less did that already, to little effect:
President Clinton confessed in "unprompted" remarks that "Iran...has been the subject of quite a lot of abuse from various Western nations. And I think sometimes it's quite important to tell people, look, you have a right to be angry at something my country or my culture or others that are generally allied with us today did to you 50 or 60 or 150 years ago."
Then in 2000, at a state dinner in Washington, Secretary of State Madeline Albright directly apologized for specific past American actions toward Iran, from our role in orchestrating the overthrow of Prime Minister Mohammed Mosaddeq, to our backing of the Shah, to our backing of Iraq in its war with Iran. Albright also highlighted President Clinton's personal belief that America "must bear its full share of responsibility for the problems that have arisen in U.S.-Iranian relations."