Once again, Irish voters are poised to vote Yes or No to the Treaty of Nice. Forgotten what that treaty is all about? Well, it is one of those all-too-frequent late-night compromises reached by EU heads of state and government that seek to slither around and through some practical problems while postponing others.

The compromise reached at Nice four years ago is important because it contains, among other provisions, all the technicalities of voting balances and power sharing among EU institutions that must be firmly in place before the Union can admit new members. Enlargement is the most important item on the European agenda, and the Treaty of Nice is its cornerstone. Without it, the accession candidates can not be invited this December to join the Union, as promised in Copenhagen ten years ago.

The Irish rejected the Nice Treaty in a referendum last year. The country's entire establishment--its government, major political parties (including the opposition), trade unions and employers--all supported a Yes vote. But the Yes backers could never articulate clearly why people should vote in favor of the Treaty. Their constituents largely ended up ignoring the issue altogether. The No vote won 54%, but only 35% of eligible voters bothered to turn up at the polls.

It is still difficult to fathom why the No vote attracted so much support, even given widespread apathy. The opposition to the Nice Treaty was and continues to be a bizarre Irish Stew of pacifism, religion, and socialism, along with some fascinating local eccentricities. And yet, despite winning the addition of a special protocol to the Nice Treaty that guarantees Ireland's cherished neutrality, Yes supporters face an uphill battle.

Outside interference should always be avoided in situations such as this. After all, one of the core freedoms of a democracy is that voters have the right to behave in ways that outsiders might deem irresponsible and incoherent. As long as such choices do not impose unreasonable or unbearable burdens on others, these democratic choices merit full respect.

But the fundamental consequences of the upcoming referendum for Europe need to be clearly impressed upon Irish voters, so that no one can later claim that they did not know what was at stake. If the Irish vote No a second time, and this leads to the postponement of EU enlargement, they would place an unreasonable and unbearable burden on Europe.

Re-negotiating the Nice Treaty would not be an option. This would open a Pandora's box of demands from all other countries. Last year's Irish referendum result prompted Italy to suggest that the EU give guarantees to member states that they would not lose financial support if poorer members are brought into the Union. This sort of thinking is the surest way to block enlargement.

The Irish people must be brought to understand that if they cannot accept the Nice Treaty, nor can they block it. A new No vote can lead to only one outcome: Ireland's departure from the institutions of the EU, one way or another. This is the true choice that the Irish now face.

There is an important parallel to this situation: in 1992, Danes surprisingly voted No to the Maastricht Treaty. The Danes got their own add-on protocols--such as a neutrality guarantee like the one given to the Irish--making it possible to opt out of certain areas of EU cooperation. This led to a new referendum, in which the Danes voted Yes.

But--and this is crucial--the Danes were told in no uncertain terms that a second No vote would lead to a situation where Denmark would have to leave the Union. If the Danes did not want the Maastricht Treaty, their choice would be fully respected. But they would not be permitted to impose their will upon their partners.

The Irish are in the same position now. It is up them to say Yes or No to the Treaty of Nice. Their decision must be respected. But they cannot be allowed to stop the enlargement process.

It would be an irony of historic proportions if a country that has benefited more than most others from EU integration should block the entry of countries in even more desperate conditions than Ireland was 30 years ago. Europe must accept the Central and Eastern European candidate countries into the Union, and must do so now. Too much time has been wasted already. The window of opportunity to create a Europe that is whole and free after a half century of division and misery may not remain open indefinitely.

Copyright: Project Syndicate, October 2002