The Taoiseach has rejected calls for the resignation of his ministers for transport and defence over their handling of attacks by peace protesters on US planes refuelling at Shannon airport.
Mr Ahern said his ministers had reacted "promptly" in stepping up security.
His comments came after 120 armed soldiers moved in to patrol the airport in a to prevent further damage to planes by protesters, and news that World Airways was rerouting 17 flights through Frankfurt instead of Shannon.
Fine Gael leader Mr Enda Kenny described the situation as a "shambles".
"Will the Taoiseach be asking for the resignation of the minister for defence and the minister for transport in view of the shambles that they have allowed to happen at Shannon?" he asked Mr Ahern in the Dáil.
"A major American airline has decided that one of our key airports is not safe. That airline has been providing jobs and security to the Shannon area for decades.
"That has now been radically cut because their planes are not safe in our hands."
Mr Kenny described the events as "nationally damaging and internationally humiliating" and accused the Government of "closing the door once the horse has bolted".
Mr Ahern rejected the calls, saying that prompt action was taken.
"As soon as we had the events of the other morning we decided to take further action," he said.
"Prompt action was taken by the Minister for Defence within a matter of 12 hours to bring in members of the Southern Command to take the necessary action and to protect planes."
The soldiers will provide 24-hour security at Shannon after a US navy plane was vandalised twice while refuelling on its way to the Gulf in the US build-up to a war in Iraq. Last week 50-year-old peace protester Ms Mary Kelly was charged with vandalising the plane, causing damage estimated at €500,000.
On Monday five more protesters were charged with damaging the same plane as it was being repaired.