It must puzzle our fellow members of the European Union why we alone of all its members felt compelled to hold a referendum before ratifying the Lisbon treaty.
During the debates in the Dail on the proposed amendment of the Constitution that was put to the people in the recent referendum, Fine Gael TD Tom Hayes asked why it was necessary to amend the Constitution in order to ratify the Lisbon Treaty.
The only explanation that he got from government spokesmen was that the Attorney General said so.
It would have been interesting to know the exact advice of the Attorney General, in particular, whether it went further than expressing doubts as to the constitutional validity of ratification without a covering referendum.
In 1987, delivering the judgment of the Supreme Court on a previous amending treaty, Chief Justice Thomas Finlay stated that the authorisation given to the State to join the European Communities (as the European Union was then described) was an authorisation to join in amendments of treaties "so long as such amendments did not alter the essential scope or objectives of the communities".
Was it not arguable that the amendments to the treaties of the European Union in the Lisbon Treaty fell within this description?
Moving the necessary legislation in the Dail, the then foreign minister Dermot Ahern remarked that previous amending treaties had heralded much greater change. Another minister described the Lisbon treaty as modest.
But Deputy Tom Hayes got no answer to his perceptive question.
When the Constitution was amended to enable Ireland to join the European Communities in 1973 nobody in government seems to have adverted to the need to make provision for future amendments of the treaties governing the Communities.
The constitutional amendment, as originally worded, protected from challenge under the Constitution all future acts of the organs of government consequential upon membership of the communities.
The Fine Gael front bench, for which Garret FitzGerald was a spokesman, insisted on an amendment that protected only those acts that were necessitated by membership of the communities.
The Fianna Fail government gave way. Under the original wording it would have been easier to argue that the Constitution did not need to be amended to enable Ireland to ratify the Lisbon Treaty.
In 1987, in a case brought by the campaigning Eurosceptic Raymond Crotty to prevent the Government ratifying the Single European Act, the Supreme Court ruled that the commitment by the Government, that they held was inherent in the Act, to limit its future discretion in matters of foreign policy was contrary to the Constitution and required a constitutional amendment.
This has made it more problematical ratifying without referendum European treaties, especially where they expand the foreign policy competence of the organs of the European Union. However, the decision of the Supreme Court, which was reached by a narrow majority of three to two overruling a unanimous High Court judgment of a three-judge High Court, has been much criticised and would probably not be followed in a future case.
It is all uncertain legal ground. But, as it turned out, the political ground also offered no certainty. The Government would have done better to proceed to ratification of the Lisbon treaty and left it to the objectors to challenge their action in the courts if they wanted to have a referendum. They could scarcely have done worse.
Charles Lysaght is a former adviser on European law at the Department of Foreign Affairs