A High Court case will challenge Shannon's use by military planes, writes Carol Coulter, Legal Affairs Correspondent.
Mr Edward Horgan is a former Army commandant who has seen service overseas on behalf of the UN. He, therefore, has first-hand experience of Ireland's role in international conflicts.
He is now taking a case against the State challenging the granting of landing rights to US planes bound for Iraq with soldiers and supplies. It is due to start this Thursday, and Mr Horgan is represented by former attorney general Mr John Rogers SC, and Mr Paul Callan SC.
A measure of how seriously the Government is taking this challenge is the fact that it has engaged no less than four senior counsel (the normal complement is two). They are Mr Paul Gallagher SC, Mr Gerard Hogan SC, Mr Brian Murray SC and Mr Donal O'Donnell SC.
If the State loses it will be deeply embarrassing given its trenchant defence of the use of Shannon in the Dáil and in public, and the evidence that the US administration places a high value on this service.
Whatever the outcome in the High Court, the case is likely to go to the Supreme Court because of the importance of the issues involved.
Yesterday, the President of the High Court, Mr Justice Finnegan, said that normally he would have arranged for it to be heard by a divisional (three-judge) court. However, resources did not permit that. It is likely, therefore, that he will hear it himself.
It is understood that the case will centre on Article 29.3 of the Constitution, which states: "Ireland accepts the generally recognised principles of international law as its rule of conduct in its relations with other states."
The preceding sections state: "Ireland affirms its devotion to the ideal of peaceful and friendly co-operation amongst nations founded on international justice and morality", and "Ireland affirms its adherence to the principle of the pacific settlement of international disputes by international arbitration or judicial determination".
The Constitution was written at a time when the development of international law was in its infancy, before the setting up of the UN, the Council of Europe or the EEC, and therefore before the coming into being of various conventions based on these institutions. This case should see some flesh put on the bones of these general constitutional principles.
The elephant in the room that will be impossible to ignore is whether the war in Iraq conforms to "the generally recognised principles of international law".
Does it infringe the UN Charter, which specifies the circumstances in which it is permissible to resort to military action? These do not include pre-emptive self-defence.
The allies have argued that successive UN resolutions on Iraq, including 1441, provide the legal basis for the war. But it has been argued by most of the leading specialists in international law, in Britain and elsewhere, that a second Security Council resolution was necessary to make military intervention legal.
The State can argue that there is a debate about this, so it is acting in good faith within the general framework of Article 29.3.
It may also argue that it is not actually supporting the war and is not "participating" in it.
The Taoiseach and other Government figures have said that they are only continuing to provide a long-standing service to the US. But Mr Horgan's legal team has sought the discovery of certain documents from the State in order to establish "the nature and scale of the use of the facility at Shannon" so this contention is likely to be disputed.
The first task in the case will be establishing what Article 29.3 actually means.
The Review Group on the Constitution, which reported in 1996, has already identified some problems with it.
For example, what exactly is a "generally recognised principle" of international law? Which principles are "generally recognised" and which are not?
Does the phrase "rule of conduct" mean that the Government and the Oireachtas must always act in accordance with such "generally recognised principles", or do they simply form a non-binding guideline?
The State is likely to stress the fact that our Constitution and domestic law is primary, and international instruments which have not been translated into domestic law have no legal weight.
This was the position taken by the High Court two years ago (in a judgment by Mr Justice Finnegan) and later by the Supreme Court.
There Joseph Kavanagh, who had been convicted and sentenced by the Special Criminal Court, obtained an opinion from the UN Committee on Civil and Political Rights that he should not have been tried there, but the Government took no action as a result, and this was endorsed by the courts, which said that the committee's views were not legally binding.
The State can also argue that the Oireachtas voted in favour of the use of Shannon, and, given the primacy granted to the Oireachtas by the Constitution, that decision is lawful.