Rarely has a visit by a head of state to Ireland excited such controversy as the brief encounter President George Bush will have with the Taoiseach, Mr Ahern, at the United States summit with the European Union in Dromoland Castle tomorrow morning.
The agenda, on the face of it, appears fairly normal. It concerns Iraq, the Middle East, economic relations, counter-terrorism and HIV/AIDS and Sudan/Darfur under preparation during Ireland's EU presidency. A separate bilateral meeting between Mr Ahern and Mr Bush will focus on Irish-US relations.
On the official level these meetings will register significant progress in improving transatlantic relations following the battering they received as a result of the Bush administration's policies over the last 3½ years. Irish public opinion in its generality - not the usual mixed bag of trendies and lefties - is deeply divided on whether Mr Bush should be accorded the traditional welcome.
A great deal will depend on how clearly and frankly existing disagreements are registered and expressed at the summit. The politics of friendship and obligations of politeness cannot silence candid criticism.
Ireland has had an effective and skilful EU presidency, one of its main objectives being to improve transatlantic relations. The Government is in a good position to do so because of this country's deep and constructive connections with the United States and Europe in the cultural, economic and political spheres.
The summit will register both sides' wish to put divisions behind them by reaching compromises. Mr Bush has adjusted his policy on Iraq at the United Nations ahead of next week's formal transfer of sovereignty, and goes to the NATO summit in Istanbul hoping to convince it to take a greater role there.
It would be naive not to wonder about the strategic purpose of Mr Bush's meeting with Mr Ahern on his pre-election visit to Ireland.
Yesterday's violence in Iraq illustrates the lack of foresight in Mr Bush's policies. Having decided to invade Iraq unilaterally, without a United Nations mandate, he broke faith with the international order of the world to which he is ideologically hostile.
The purported justification was the false presumption that Iraq possessed weapons of mass destruction. News about the torture of prisoners has shocked opinion in Ireland and Europe and in the US itself. As a result the Middle East has been further destabilised, terrorist movements given a new base, and an intransigent Israeli government a greater motive to avoid real resolution with the Palestinians.
The rationale for all of this is the war on terror. Mr Bush has failed to secure a real international consensus to prevail in this war. He may not see this but other European leaders can. The President of the US should heed the criticisms that he encounters in Ireland in his own self-interest. For ourselves, protest must be restrained and peaceful, lest it be wasted.