Anchor Lisa Mullins speaks with Borzou Daragahi, Middle East correspondent for the Los Angeles Times, about reaction in Iran to President Obama's speech, and about last night's presidential debate in Tehran between the incumbent and his main challenger.

Twenty years ago today came word of the death of Iran's supreme leader, Ayatollah Khomeini. Journalist John Hockenberry recalls the events surrounding the death and funeral of the Ayatollah. Hockenberry was one of many American reporters covering the story from Tehran.

The answer to today's Geo Quiz is Cedar Rapids, Iowa. The city is home to the Mother Mosque of America, an Islamic cultural center that is one of the oldest mosques in America. It's one of the approximately 1,200 mosques in the United States that President Obama referred to in his speech in Cairo today.

Twenty years ago today, Chinese troops cleared Tiananmen Square. Hundreds, possibly thousands of people were killed in and around the square. Chinese students had been calling for democracy and free speech. The World's Mary Kay Magistad reports from Beijing on an ongoing legal dispute over a documentary about the 1989 Tiananmen crackdown called "The Gate of Heavenly Peace". The case pits the filmmakers against one of the student demonstrators.

The BBC's Chinese Service asked people to share some of their thoughts and recollections about China's Tiananmen crackdown 20 years ago today. Anchor Lisa Mullins introduces us to two of them.

Hong Kong vigil for the victims of the 1989 crackdown