The Government is not going to apologise for any role it had in helping to remove Saddam Hussein, the Taoiseach has insisted in the Dáil.
Mr Ahern rejected claims by the Socialist Party TD, Mr Joe Higgins, that Government policy on the use of Shannon Airport by American military was dictated by a "falsehood" from the US administration.
The row broke out over comments by the US Defence Secretary, Mr Donald Rumsfeld, that Iraq might have destroyed all its weapons of mass destruction before the war.
Mr Higgins, who claimed that "the parliament and the people were misled", asked: "Does the Taoiseach not mind, that as leader of this country, he repeated a falsehood given to him by his friends in the United States?"
During sharp exchanges, Mr Ahern said it was "not a question of being misled".
He would make no apology for anything, he said, especially given that 14,000 victims were killed in one day by Saddam and his weapons of mass destruction.
Whatever role Ireland played was small, but "we are not going to apologise for any small role we might have played in helping to remove a dictator who made his people suffer for 20 years, carried out horrific acts and didn't care about democracy. He is gone now and thank God for that."
Mr Higgins said Mr Rumsfeld was the "same person who revelled like a psychopath in his strategy of shock and awe as the entire infrastructure of a nation was blown to rubble by US and British bombs". He had, with President Bush, "dictated that thousands of Iraqis would be slaughtered, children blown from their beds and civilians ripped to shreds by cluster bombs, allegedly because Iraq had weapons of mass destruction and posed a threat to the world".
The Dublin West TD said that in a Dáil motion in March, the Taoiseach "condemned the refusal of the government of Iraq to comply with its obligations to disarm under numerous resolutions". That motion and the Taoiseach and Tánaiste's speeches were based on a "falsehood" perpetrated by the US administration.
Mr Ahern accepted this falsehood and on that basis, "facilitated the invasion of Iraq through the use of Shannon Airport", said Mr Higgins, who called for the Taoiseach to "apologise for the fact that inadvertently or otherwise, he misled the Dáil and the people by giving credence to a palpable falsehood".
Mr Ahern said, however, that it was "amazing how some people are so glad to argue the case for a dictator who was responsible for using torture and killing thousands of his own people". He added that he was "proud of the actions we took in supporting the UN Security Council and anything else we did in this regard".
Some of the "innocent victims of Saddam Hussein were killed by people doing so on the strength of Fianna Fáil beef, including that sold by ministers of the party who did business with the beast of Baghdad", the Socialist Party TD said.