Mr Ahern has shown his hand on Iraq, arguing that US troops at war outside the UN framework should still be allowed to use Shannon Airport, reports Mark Brennock, Chief Political Correspondent.
Standing on the White House lawn yesterday, the Taoiseach set the stage for what may become one of the most contentious national debates on foreign policy since the foundation of the State.
His comments straight after a meeting with President Bush left little doubt as to what his intention is: if the US goes to war outside the UN framework, he appears determined, despite strong and active public opposition, to allow their military forces to continue to land and refuel at Shannon Airport and to overfly Ireland.
Shannon is the only practical issue at stake in relation to Ireland's stance on Iraq. Mr Ahern said yesterday that he had told President Bush that Ireland "could not obviously engage or involve ourselves in any military action" against Iraq without a second UN resolution.
But neither President Bush nor anybody else was expecting the Irish Army to join an invasion force. What they want is to be able to continue to use Shannon Airport. Yesterday, for the first time, Mr Ahern laid out all the arguments for allowing them to do so.
US planes had landed at Shannon during the Vietnam War and the military action in Kosovo, despite the lack of UN resolutions, he said. Staunch war opponents such as France, Germany and Arab states were not withdrawing their facilities - so why should we? "We would be the only country in the free world that would be withdrawing something," he said.
The Green Party's John Gormley challenged this line in the Dáil on Wednesday. France and Germany were allies of the US in NATO, he said. We were not.
Mr Ahern is right to say we are the only country that would be withdrawing something. Austria, the only other EU "neutral" where the provision of facilities to US troops has been an issue, declined to give US troops transit facilities from the start. Switzerland - as it did in the 1991 Gulf War - has also banned US military overflights unless they are on a humanitarian mission of some kind.
A failure of the Security Council to agree a second resolution would present the Government with the choice it most desperately wanted to avoid. If it was to deny the use of Shannon, it fears it could damage the strong economic and political relationship with the US.
That fear is real, despite the view of some, including former minister for foreign affairs, Mr David Andrews, that the Americans would understand our position.
However, to allow the use of Shannon - as Mr Ahern yesterday argued for - would provoke substantial public anger. The Government was shaken by the size of the anti-war protest in Dublin last month, and the Irish Times/MRBI opinion poll showing voters opposing the use of Shannon by the US military in all circumstances, and by a three-to-one margin if there is no second resolution.
In anticipation of a stormy debate and more public protests, Mr Ahern pitched his comments yesterday at the general public. Pointing to the precedents and the stance of France and Germany he said: "I think that prior to us making that decision it is only right that the Irish public understand that position."
He outlined for the first time the argument to be deployed if he is to seek Dáil approval for the use of Shannon during a non-UN-mandated war. That is that Ireland does not support the war, but that the continued provision of Shannon does not amount to support.
"It never has," he said. "We have had many precedents, many examples of that in the last 45 years or so. We have had issues around Vietnam, in Kosovo - we did use our flyover space and not only that, landing rights."
Government practice since 1955 has been "that if there was no resolution we didn't engage in military action or support military action . . . But we didn't withdraw our flyover or landing facilities and of course I think it is only right that I point that out to public opinion. This would be a departure."
Having strongly outlined the argument, he insisted the Cabinet had not made a decision. He said this would have to be done very quickly. Should a war finally begin within a few days, the Cabinet may have to make the decision as early as next week.
The Government Chief Whip, Ms Mary Hanafin, said this week that the Dáil - not due to meet again until March 25th - could be recalled at 48 hours' notice if necessary. It is conceivable that this could happen next week, precipitating one of the most bitter debates in recent years.
If it comes to it, Mr Ahern is almost certain to win a Dáil vote. Despite some discontent on his backbenches, there has been no evidence so far that any conscientious objector would vote against the Government.
The emergence of a second UN resolution from the Security Council could yet save the Government from having to make this most contentious decision. But Mr Ahern has clearly indicated that the policy is as reported in this newspaper a month ago: that if it comes down to it, Ministers have resolved that there are no circumstances in which they will withdraw the use of Shannon Airport from the US military. "Our bottom line is we will do what the Americans want," a source was quoted as saying in a report in this newspaper which the Taoiseach disparaged at the time.
"What the Americans want" is to continue to use Shannon Airport. In Dublin a few weeks ago US special envoy Mr Richard Haass made this clear. Shannon was "extremely useful" because of its capacity and its location. "Are there alternatives or substitutes? Yes. Would they be as good? No. Shannon is one of the most capable facilities in this part of the world."