A response to last week’s terrorist attacks in the United States must not be merciless or indiscriminate, the Taoiseach has told a special sitting of the Dáil.
"The temptation immediately to lash out with all available military might has been resisted", Mr Ahern said.
"I am certain that the United States will wish to avoid civilian casualties that might indeed compound an already difficult problem. They understand the importance of ensuring that the response to these horrendous events be proportionate, measured and focused on the pursuit of justice".
The Dáil was recalled to discuss the situation following the attacks on in New York and Washington and threatened military strikes against Afghanistan’s ruling Taliban and Islamic fundamentalist Osama bin Laden.
Mr Ahern said: "In addressing the immediate crisis, the international community must also ensure that we are not sowing the seeds for even greater catastrophes in the future. It is imperative that whatever actions are taken are clearly seen as measured, as targeting terrorism at its source and based on clear evidence".
The Tánaiste, Ms Harney, said there were "strong grounds for believing we are dealing with Osama bin Laden" and that the United States had the right to engage in "an appropriate military response".
She said: "It is important that we in Ireland make our contribution to the international effort, both through the United Nations and directly through our relationship with the United States".
She added: "Terrorism has disfigured the politics of this country for much of the last thirty years." She asked those organisations on the island seeking to engage in political activity while keeping the terrorist option to move away from violence. "And don’t just say it: do it. And that means no more guns, no more bombs and no more punishment beatings."
Labour Party leader Mr Ruairí Quinn said the US atrocities were "deeply felt in Ireland" and that the calling of a National Day of Mourning last Friday was "quite appropriate".
"The uniquely respectful way in which the day was observed was a vindication of that decision," he said.
Mr Quinn said any military response should "be done in accordance with international law and on the basis of the greatest degree of international consensus".
Fine Gael leader Mr Michael Noonan said: "The atrocities in the United States of America last week represented an attack, not just on the United States itself but also on democracy as a whole.
"The symbols attacked may have been symbols of world trade in the case of the Twin Towers in New York or superpower in the case of the Pentagon. But the attacks were attacks on ordinary people."
Full text of the Taoiseach's Dáil statement
Full text of Tánaiste's Dáil statement
Full text of Michael Noonan's Dáil statement
Full text of Ruairí Quinn's Dáil statement