Because we are the only country proposing to ratify the Lisbon Treaty by referendum, the entry into force of this treaty for the whole of the 27-member European Union is entirely dependent on the vote of the Irish electorate, writes Garret FitzGerald.
And given the herculean efforts made over several years by all of Europe's political leaders to overcome the 2004 setback to the ratification of the earlier mis-named "constitutional" treaty, an Irish veto on this reform treaty would have hugely negative effects upon our situation within the union.
In economic terms we have been the single largest beneficiary of EU membership, and alone among our political parties, Sinn Féin, with minimal electoral support, is opposed to it; so a negative vote by our people would be seen throughout Europe as incomprehensible - and indeed perverse.
Of course, Irish public opinion has been consistently pro-EU, but referendum votes are frequently influenced by factors other than the issue actually before the electorate; most frequently, it would appear, by the popularity or unpopularity of the government then in office, which can greatly influence the proportion of supporters of a proposal who turn out on referendum day.
Referendum turnouts tend to be lower than those for general elections: on the 20 occasions on which people have been asked to vote in a referendum, an average of only 50 per cent have voted. On two of these 20 occasions the proportion of the electorate voting fell below 30 per cent.
In the first referendum on the Nice Treaty just 34 per cent voted - so that although on that occasion only 18.5 per cent of the electorate voted against the treaty (actually a one-tenth smaller proportion than had voted against the previous Amsterdam Treaty), the proposition that the Nice Treaty be ratified was nevertheless lost.
This happened simply because the efforts of the government (and also of the opposition) to explain why that treaty should be ratified had been so inadequate they persuaded less than 16 per cent of voters to come out to vote for it!
On occasions like this the people must never be taken for granted. Rightly, they expect those politicians who voted through the Oireachtas any given referendum proposal to explain why in their view the electorate should endorse their proposition.
In relation to referendums on EU treaties, a particular responsibility rests on the principal Opposition party, Fine Gael. First of all, Fine Gael has traditionally been more enthusiastic about the European Union than Fianna Fáil, some of whose members in the past have allowed their more radical nationalism to influence negatively their attitude to the EU.
In the first, May 1972, referendum on joining the EU, Fine Gael played a more prominent role than did the members of the Fianna Fáil government who had negotiated our entry terms. And I think it is fair to say that the first Nice referendum might not have been lost if the more pro-European Fine Gael party rather than Fianna Fáil had been in government at that time.
But there is another, more particular, reason why Fine Gael, and also Labour, need to be active in this referendum. There is bound to be a danger that some voters would allow resentment against a Fianna Fáil Government, currently undergoing a downturn in its popularity for reasons that have nothing whatever to do with Europe, to influence them to "punish" that Government by abstaining or even in some cases by voting against this Lisbon Treaty.
In such circumstances the Opposition parties have a potentially important role to play in encouraging the electorate to distinguish between the importance of ratifying this treaty in the national interest and any temptation they may feel to hit at an unpopular government.
As we are the only country to hold a referendum on the Lisbon Treaty, we are likely during the campaign to be inundated with continental (and perhaps also British) Eurosceptics, attempting to use this opportunity to pursue in Ireland their domestic nationalist frustrations about the EU. I would not worry too much about this, for our electorate will not be easily swayed by such external political interventions - which may indeed prove counter-productive from the point of view of Sinn Féin and any other native Eurosceptics.
However, a corollary to that is that the presence here during the campaign of prominent people from other EU states urging the ratification of this treaty might prove equally negative for those who favour ratification. Such soundings of opinion as I have been able to make suggest that the Government may be naive in thinking that visits by European leaders such as the German chancellor between now and the referendum would help to secure a positive outcome.
While Angela Merkel, in particular, is respected here, her presence during the campaign period could be presented by our native Eurosceptics as an attempt by a "foreigner" to pressurise voters.
The Government has envisaged holding this European referendum in tandem with another on children's rights - just as in 1998 the Amsterdam Treaty referendum was held simultaneously with that on the Belfast Agreement.
But even if all-party agreement were to be reached in due course on the terms of the children's rights referendum, I am not sure that such a combination of referendum issues would be a good idea - for there is bound to be some controversy on that issue, and cumulating opposition on two quite separate issues might not be helpful.
Moreover, if it is proposed that the two referendums be held on the same day, uncertainty for some months ahead surrounding all-party agreement on the children's rights issue would have the effect of leaving unclear the date of the Lisbon Treaty referendum. That would, I feel, be unwise, as it would inhibit the initiation of both the political and civil society campaigns in favour of the treaty.
And the sooner the groundwork for those campaigns is laid, the better. For well before we face an inevitable further misleading campaign about EU "militarism", we need to present to our people the positive side of our Army's peacekeeping activities, both in parts of Europe, such as Kosovo, and also elsewhere in the world.
For Irish people rightly take pride in the professionalism of our Army's peacekeeping activities, whether under the auspices of the UN, the OSCE, or now the EU itself, and of the unique way in which Irish soldiers engage constructively with local populations wherever they serve under any of these auspices.
Well before attempts start to be made to put us on the defensive on this aspect of our EU involvement, the electorate should be told a lot more about this positive aspect of Irish military activities.