For those of us born shortly after the second world war, who lived through four decades of Cold War, and who could reasonably expect to see only the development of a closer western European political union, today's enlargement of the European Union is a cause of profound thanksgiving, writes Martin Mansergh.
It is one of the great moments in three millennia of European history.
It is symbolically appropriate that to the most westerly member-state should fall the honour of welcoming the Baltic states of Latvia, Estonia and Lithuania, the central and eastern European countries of the Czech Republic, Slovakia, Poland, Hungary, and Slovenia, and the Mediterranean islands of Malta and Cyprus (part of) into the European Union.
That such countries look across Europe to Ireland as a model for rapid development helps to bind the Union together.
We in turn look across to them, and see both new competition and new markets. We wish the new members the opportunities that Ireland has enjoyed.
For several years now, the Taoiseach and Minister for Foreign Affairs have been intensifying relations with the accession states, one reason they are now so familiar with the Irish experience.
We are constantly told that the important objective is social cohesion, closing the gap between the rich and the poor. In income terms, Ireland has done that in Europe over the last 17 years. Matching the accumulated wealth of the more developed countries will take continued growth over a long period.
It will never be achieved by rushing headlong into constructing the most elaborate, costly, and ultimately unsustainable system of social protection on the continental model. The key is to maximise tax revenues and minimise tax rates and steadily build on a sound financial base.
President Mitterrand's initial idea in 1989-90 of an outer European confederation round an inner core has not been pursued. A fully inclusive policy has been followed, both on the euro and enlargement.
The new members deserve the same generosity of funding that Ireland enjoyed since 1989, which is now rapidly tapering off, as its objective has been largely fulfilled.
The Union will probably settle for a new ceiling for funding somewhere between the 1 per cent of GNP demanded by six net contributory states and the 1.24 per cent (just below the permitted ceiling of 1.27 per cent) sought by the EU Commission.
There will be dissonant voices on the margins. Anthony Coughlan's National Platform issued a press release on April 26th, saying "Welcome to our EU prison-house of nations". In the looking-glass world of political ideology, it is apparently the EU with its peaceful democratic values and prospective freedom of movement that is the prison-house, rather than the repressive totalitarian régimes that suppressed all dissent and did not allow its citizens to travel to the West, from which the majority of accession countries have only recently escaped.
Similarly, the EU collectively, and larger states in particular, are accused of imperialism, as if the present situation were not a vast improvement on the warring imperialism of the pre-1914 British, French, and central European empires.
Mr Coughlan performs brilliantly the public service of devil's advocate, in the absence of any significant political party prepared to adopt an out-and-out opposition to EU constitutional development, and wins the occasional victory, though not the war.
We should be grateful for his prison-house analogy. It clearly illustrates the ambition of the Eurosceptics to "release" nations like Britain and Ireland from the EU, and preferably wreck it altogether. The next appointed battle will be referendums on the constitutional treaty.
Ireland is the living proof that the alternative of national independence in isolation is not enough. Nation-states, acting on their own, will often frustrate each other. As Dan O'Brien pointed out in this paper yesterday, it is smaller countries that suffer most from the absence of agreed rules.
The framework of the European Union has allowed Ireland to develop and flourish and to play a larger role in the world. The peoples of the applicant states know what they are doing in joining the EU, and see it as a passport to a happier, more secure future.
The constitutional treaty ensures that a union of 25 can continue to function and take decisions. While on the face of it smaller member-states will have more influence, all member-countries will need to show a degree of restraint and mutual consideration in pursuing national interests, so that confidence in the functioning ability of the enlarged EU can be quickly built up, and more drastic alternatives like a two-speed Europe or a directory put away.
Ironically, the EEC had its most fractious period during the 1960s stand-off with de Gaulle's France, when it was only six-strong.
It is disappointing that the Greek part of Cyprus voted down the UN unity plan. It demonstrates how unity is or is not brought about in a divided territory. It is not about the majority community imposing its will, but about agreement to which people of both parts and both traditions can subscribe.
Hopefully, there will be another opportunity, but, meanwhile, the EU and the international community are bound to adopt a more pragmatic and conciliatory approach to Turkish Cyprus. There are lessons for those of us who would like to see a united Ireland by agreement. Terms that might suit the long-separated Northern part of an island may not suit the more settled and prosperous South.
This is a day, when celebrations should be much louder than protests, a great day for 10 countries, a great day for Europe, and a great day for Ireland.