There has been much debate over whether the EU's Brexit position on Irish unity is of great political significance or merely restates the obvious.
The European Council confirmed last week that it would regard a united Ireland, brought about via the Good Friday Agreement, as an enlarged Republic of Ireland, with no need for the North to reapply for EU membership.
It has always been obvious that the 1998 agreement could deliver Irish unity.
International law is clear that, in this event, the current Republic should be the continuing state.
However, the nature of Irish unity has yet to be clarified because - beyond how to achieve a united Ireland - the agreement’s wording is ambiguous.
It only says North and South shall separately exercise their right to self-determination to “bring about a united Ireland”.
Brexit makes it important to have a signposted route back into the EU for people in Northern Ireland.
In a poll before last March's shock Stormont result, eight per cent of unionists indicated they would consider a united Ireland due to Brexit.
Next month’s Westminster election could provide further evidence on how many unionists rank the EU over the union.
What has been swamped in this debate, amid its inevitably European focus, is the idea that a united Ireland would be a new Ireland - or “a completely new state”, to use a commonly-heard phrase.
The promise of a new state has underpinned most serious discussion on unity to date
This is how republicans have long promoted unity to unionists and to a certain extent to themselves.
No discussion on the issue has been complete without a specific assurance that the South cannot simply swallow the North.
Talk of federalism, secularism, Commonwealth membership and even a new capital invariably follows.
You can always sort the wheat from the chaff in these conversations by asking if the new Ireland should have a new flag.
An assurance that the orange in the Tricolour already represents unionists feels like a fair indication of what life in a united Ireland might actually be like, although perhaps not in the way the speaker intended.
Any mention of socialism is another cue to nod slowly while backing away.
In any case, the promise of a new state has underpinned most serious discussion on unity to date.
Unionists are regularly urged by mainstream nationalists to negotiate their place in a new Irish state ahead of time, from a position of relative strength.
No doubt kindly meant, this advice carries the unfortunate subtext of: “Deal with us now, before we have the numbers to ignore you.”
However, the explicit inference is that there is meaningful scope for negotiation - so much so that large numbers of unionists might find its possibilities alluring.
Encouraging such negotiation was Dublin's official unification policy from the 1960s until the Good Friday Agreement, and Brexit seems to have brought this thinking back with a vengeance. Enda Kenny sought unionist attendance at an "all-Ireland dialogue" last year, while the Oireachtas committee on the implementation of the Good Friday Agreement is now reportedly proposing a "New Ireland Forum Two".
All of this sits somewhat oddly with the idea that a new Ireland would be a Republic of Ireland Two.
Major change
The Brussels position on unity does not preclude major change.
EU states rewrite their constitutions all the time. France declared a new republic one year after joining the EEC, without invalidating its membership.
But Brussels has undeniably altered the context of change, not least by doing so at the request of Dublin.
Whatever claims are made for a prospective united Ireland, in EU terms it will be the Republic writ larger.
This will be seen as a main plank of unity’s appeal, by undoing Brexit in the North.
Is it wise to give the issue of Irish unity so much sudden clarity?
A continuing Republic could also become critical to reassuring voters in the South, where under the terms of the Good Friday Agreement a Border poll on Irish reunification must also be held.
As it stands, from the moment unionists lose such a poll in the North, the self-determination of both parts of Ireland will become a southern takeover on behalf of the entire nationalist population, with any allowances for unionists falling very much into the category of generous concessions.
Of course, that could also be seen as a statement of the obvious.
The divide to be addressed is between unionism and nationalism, not North and South.
Unionists have never shown the slightest interest in advance negotiations on unity, so they are unlikely to open discussions until they are outvoted in a Border poll, whereupon there will be no more “North” to accommodate.
But is it wise to give the issue of Irish unity so much sudden clarity?
The idea of a completely new Ireland has been a vague yet venerable paradigm around unity since partition.
Unionists stubbornly regard it as insincere, but nationalists expect unionists to be stubborn and unionists expect nationalists to be insincere, so in our own odd way it has softened our quarrel.
Now a row between London and Brussels has forced us to let daylight in on magic.
We may find that, in Ireland, that is politically significant.