FILE - In this Sept. 24, 2007 file photo, Iranian President Mahmoud Ahmadinejad speaks at Columbia University in New York. As Ahmadinejad's successor Hasan Rouhani prepares to address the United Nations for the first time on Tuesday, he has already made a deep impression on world leaders with his markedly milder tone and apparent willingness to reopen negotiations with the West on Iran's disputed nuclear program. In contrast, Ahmadinejad was jeered and pilloried during his eight visits to U.N. headquarters in New York. (AP Photo/Stephen Chernin, File)