Mr Tony Blair responded well to history's opportunity yesterday. Eight months ago, it would have seemed impossible that Dail Eireann and Seanad Eireann should accord the signal honour of jointly addressing both Houses of the Oireachtas to the leader of a British government. It was no less improbable that a British premier might consider it wise or appropriate to accept such an invitation. The scale and extent of change in Irish-British relations since then was mirrored in the enthusiastic response to Mr Blair's words yesterday morning in Leinster House.
Political rapprochement apart, that response probably had something to do with the Prime Minister's palpable aura of energy and his compelling speaking manner. Much of what he had to say was prescribed to fit the solemnity of the occasion. But to the listener, there were qualities of conviction and authenticity when he stressed the new beginning in relations between the two countries as well as the agenda of common interests which they share, especially in relation to Europe. And there was good, old-fashioned audience-bonding when he recalled childhood holidays in Donegal, his first taste of Guinness in an Irish pub and his mother's nativity above a hardware shop in Ballyshannon.
Had there been swifter progress towards the creation of new structures under the Belfast Agreement, it is certain that the Prime Minister's address would have acclaimed it. As it was, he found himself obliged to look to the "prospect" of a peaceful, long-term future "for Northern Ireland and the whole island of Ireland" - rather than the attained reality. But the language was moving and powerful. Ireland and the United Kingdom are two modern countries, now well capable of putting their often-troubled past behind them, he declared. "We have both grown up now. A new generation is in power in each country".
Irish people and English people do not always find it possible to speak to each other - or about each other - without faux pas. The Englishman may revert to type, however unintentionally, as the former ruler or as the one who represents the larger, more powerful country. The Irishman may be too swift to the defence, responding to some slight, real or imagined. There were no such dangers in Mr Blair's address. As warmly as he welcomed Ireland's emergence into a new era, he enthusiastically outlined Britain's emergence from its "post-colonial malaise, modernising, becoming as confident of its future as it once was of its past".
There are few families in either island which are wholly without links in the other, which do not have a grandparent or great-grandparent or a connection through marriage which spans the Irish Sea. And these links of flesh and blood have continued through centuries of political divergence and enmity - even through periods of open warfare. As the great historic compromise in the contested ground of Northern Ireland takes shape, the possibility now emerges for the first time of a complete normalisation of relations between the two peoples, as described yesterday by Mr Blair.
In this context, it is intriguing to consider whether Irish opinion may be ready to consider rejoining the Commonwealth which it left upon the proclamation of the Republic. The Taoiseach, Mr Ahern, was circumspect on the issue in his Times interview, published yesterday, saying that he would not seek to suppress a debate on the idea. Yet there will be speculation as to why and how it has been raised at this time. Mr Ahern's views will have sent minor shock waves through certain elements of his own party. But they might be reminded that it was not Mr de Valera's choice to lead Ireland out of the then "British" Commonwealth in 1949.
The Commonwealth now numbers several republics in its ranks and it has long abandoned all of its imperialist associations. A decision to rejoin would be a valuable reassurance to many unionists who still fear this State's ambitions. The Taoiseach has called for debate on the question. It is likely we have not heard the last of it.