InsidePolitics:The Taoiseach amused the guests at the St Patrick's week reception at the Irish Ambassador's residence in Washington on Thursday night by remarking that his best friend was Ian Paisley jnr, who was there among the throng, rubbing shoulders with a cross-section of Irish and American political opinion.
Ahern, however, had a sting in the tail, saying that Paisley would remain his best friend until March 26th but, depending on what happened on that date, neither of them might wish to be friends afterwards.
The edge to the Taoiseach's remarks arose from the fact that he had just had a short private meeting with Paisley and it seems the discussions did not go all that well. Paisley himself, though, seemed in good humour afterwards and the very fact that he chose to attend the Irish Embassy is a sign of how much times have changed.
The tantalising closeness of a deal between the DUP and Sinn Féin to run Northern Ireland between them was the underlying theme of the Taoiseach's visit to Washington.
President Bush told the Taoiseach after the ceremonial presentation of the bowl of shamrock at the White House yesterday: "I cannot thank you enough for your strong leadership in resolving the issues of Northern Ireland, and I stand ready to help."
Leading members of Congress, from Speaker Nancy Pelosi to senators Hillary Clinton and Ted Kennedy, echoed the same sentiments and gave the Taoiseach great credit for persevering with the search for a solution.
Ahern received emotional good wishes from Irish-American politicians for the weeks ahead. At the lunch on Capitol Hill, hosted by Pelosi on Thursday, the recently-elected governor of Maryland, Martin O'Malley, sang the American national anthem and followed it up with the Irish national anthem, in Irish.
O'Malley is a potential future president and it appears there is yet another generation of Irish-American politicians who are committed to doing what they can for the country of their ancestors.
For all that, there is no guarantee of a positive outcome on March 26th and, even if there is a deal to share power on that day, there is no guarantee that it will last. One problem is that neither side is quite sure what secret assurances may have been given to the other.
Speaking at the Council on Foreign Relations in New York on Wednesday, Ahern made a glowing reference to Tony Blair, saying that he had done more for Ireland than any other British prime minister, including Gladstone.
This is not a sentiment universally shared among nationalists or unionists. Some would suggest a more appropriate comparison would be with Lloyd George, who brokered the Anglo-Irish Treaty of 1921 by telling lies to both sides and who left office in a scandal about the sale of peerages.
Séamus Mallon, the former deputy first minister in the first, failed, powersharing executive established under the Belfast Agreement would appear to take the latter view. "This man with a moral dimension to everything, who applied morality to nothing. I got increasingly to the point where I wouldn't have taken his word for anything. And that was as a result of the dealings that I had with him," Mallon told the Guardian newspaper in an interview this week.
Mallon is entitled to feel bitter at the way in which moderate unionism and moderate nationalism were sold down the river, and not just by Blair. "It wasn't clumsiness. It wasn't judgments that went wrong. It was strategy. You had [ Jonathan] Powell and others in Dublin who had decided that to make this work you had to dispense with middle unionism and middle nationalism. I think it was as calculated as that," he said. The question now is not just whether the extremes, having destroyed the potential for a meeting of minds in the middle ground, will be able to agree on a share of the spoils on March 26th, but whether they will be able to make it work in the aftermath.
The form of administration established by the Belfast Agreement was probably the only possible model in the circumstances but it is not a recipe for the creation of a healthy society. The parties get their seats in the executive by right based on the strength of their vote and there is no requirement for them to share collective responsibility.
Given the polarised nature of society in the North, the lack of any imperative for the politicians to develop a close working relationship or a shared understanding of issues could be a problem.
Still, in the circumstances, a decision by Ian Paisley snr to share power with Sinn Féin has the potential to create a whole new dynamic which would transform the political and economic situation.
There is some irony in the fact that the DUP is now making the demand for a reduction in the North's corporation tax to 12.5 per cent, to create a common 32-county rate.
If it is equally pragmatic in its approach to powersharing, a deal may well be done on March 26th. It may all come down to whether Mr Blair's secret deals with both sides unravel under pressure.