Path to Irish unity now much clearer but major obstacles still lie ahead
Brexit is an epoch-defining moment for Britain and the British people in terms of what it reveals about how they see themselves, their relationship with the rest of the world and the very constitutional nature and survival of the United Kingdom.
From an Irish perspective, Brexit is equally significant. It will rattle the Irish State and will also challenge perceptions about things that were once regarded as certainties - the invisibility of the border, free movement and trade.
These may end up being resolved in a manner that defuses their potential to exacerbate divisions within the North, but for now they remain serious areas of concern for an Irish Government and people only just emerging from a painful period of austerity.
For nationalists in Northern Ireland, it is very troubling in terms of seemingly creating another barrier to integration on an all-island basis, but it also has the potential to shake Ulster unionism to its very foundations if it sets in train a process leading to Scottish independence.
There is potential for the Fresh Start deal between the DUP and Sinn Fein to be derailed as European funding disappears without the promise of full compensatory funding from a British Government to replace the programmes that made Northern Ireland a net beneficiary from EU membership.
If Brexit leads to an independent Scotland, then the path to an all-Ireland state becomes much clearer, as it profoundly undermines the rationale of continued attachment to a political entity that is reduced to simply England with a Welsh appendage.
Therefore, it is no surprise that senior Sinn Fein leaders, including the Deputy First Minister, wasted little time in demanding that a border poll be held in the North, using the same argument as SNP leader Nicola Sturgeon - namely, that the Northern Irish electorate's clear desire for remaining in the EU has been denied by the Brexit vote. Irish republicans will look on with envy at Nicola Sturgeon and the SNP, who are braced to mount a fresh referendum campaign with a credible prospect of obtaining their goal of independence.
Yet, there is no realistic prospect of an Irish border poll being won at this time. In fact, the compelling evidence of nationalist disengagement over the past six years from electoral politics indicates that Sinn Fein and the SDLP need to rethink their approaches if they are to reignite interest amongst their electorates.
A border poll in which few believe a positive outcome is possible is hardly likely to motivate nationalists and could end up being counter-productive if it delivers a decisive unionist victory, which is very likely given the differential turnouts between the two communities at every recent election.
Consequently, republicans would be better engaged using this time to capitalise on the opportunity to position Irish nationalism as the voice of progressive opinion throughout Ireland, and particularly in Northern Ireland, developing a vision of what a united Ireland would look like as a full EU member.
This must entail working to remove the obstacles to unit,y which include the absence of an Irish national health system in the South, developing and delivering effective and tangible all-Ireland policies and strategies across all areas of governance which demonstrate the benefits of such a move, as well as promoting a vision of a shared and equal Northern Ireland within a united Ireland.
The priority for northern nationalism must be getting its house in order, then building a momentum within both jurisdictions on the island for unity in the present generation.
A border poll now is what the Americans call a "Hail Mary option" - i.e. a play made in hope of a miracle.
The road to Irish unity is clearer as a consequence of Brexit, but that doesn't mean the journey is going to be any shorter - or less challenging.
Chris Donnelly is a political commentator