The Iranian president, who rose to applause, opened his 30-minute address with an Islamic prayer. Taking his criticism on the chin, Ahmadinejad said Bollinger's introduction of him was an insult to information and the knowledge of the audience, and in turn accused Bollinger of 'unfriendly treatment' under the influence of the US press and politicians.

Bollinger asked hard questions to the head of state, most of which Ahmadinejad answered through an interpreter with more questions.

On his denial of the Holocaust, Ahmadinejad said, 'I'm not saying that it didn't happen at all. I said, granted this happened, what does it have to do with the Palestinian people?' and argued that since there no 'absolutes in academia', a 'different perspective' was necessary on the Middle East.

When Bollinger asked him, 'Why is your government providing aid to terrorists? Will you stop doing so and permit international monitoring to certify that you have stopped?' Ahmadinejad replied: 'I want to pose a question here to you. If someone comes and explodes bombs around you, threatens your president, members of the administration, kills the members of the Senate or Congress, how would you treat them? Would you reward them or would you name them a terrorist group? Well, it's clear. You would call them a terrorist.

'If you have created the fifth generation of atomic bombs and are testing them already, who are you to question other people who just want nuclear power. I think the politicians who are after atomic bombs, politically, they're backward. Retarded.'

On his country's policy on Israel, Ahmadinejad said Iran could not recognise Israel since it is based on 'ethnic discrimination, occupation and usurpation and it consistently threatens its neighbours.'

The event's moderator, Columbia dean John H Coatsworth, too had some tough questions to ask. A sample of the exchange:

'Do you or your government seek the destruction of the state of Israel?'

Ahmadinejad: 'We love all people, we are friends of the Jews. There are many Jews living peacefully in Iran.' And, for good measure added that the Palestinian nation should be allowed a referendum to decide its own future.

When Coatsworth sought a 'simple yes or no', Ahmadinejad shot back: 'You ask the question and then you want the answer the way you want to hear it. I ask you, is the Palestinian issue not a question of international importance? Please tell me yes or no.'

The answer, surprisingly, found many takers among the students who came out with a ringing round of applause.

Ahmadinejad then connected the September 11, 2001, terror attacks on the US and a solution to Iraq and Afghanistan. 'If the root causes of 9/11 are examined properly -- why it happened, what caused it, what were the conditions that led to it, who truly was involved, who was really involved -- and put it all together to understand how to prevent the crisis in Iraq, fix the problem in Afghanistan and Iraq combined.'

As he wound up his speech, Ahmadinejad invited the Columbia faculty and students to visit any Iranian university. 'We will give you the platform, we will respect you 100 percent. We will have our students sit and listen to you, speak with you, hear what you have to say.'

Image: Ayton Eller holds a sign he made at a pro-Israel/anti-Ahmadinejad protest outside the United Nations headquarters in New York on September 24.
Photograph: Nicholas Roberts/AFP/Getty Images