‘Because of the nonsense made by the inclusion of Britain,” an Irish civil servant wrote of a 1960s cross-Border initiative, “we shall have to reopen the can of worms again”. Similar remarks would be appropriate in Dublin and Belfast today.
Just as the Belfast Agreement neared its 20th birthday, the Brexiteers and their DUP followers unexpectedly gave our island’s kaleidoscope an unexpected shake.
As the pieces settle over the next few years, it is time for a new departure in the Republic's relationship with Northern Ireland, to imagine and plan a united future that all of Ulster society could want to share.
There is no obvious way to avoid some hardening of the Border that snakes 300 miles across the fields of Ulster. At the very least, there will be uncertainty and inconvenience for families, communities and business.
The British government’s intention to leave the customs union and the single market, and their emphasis on strict immigration control, means that the Border may again become a scar.
There was little concern for any of that in the Brexit referendum. To say Northern Ireland barely registers in British public discourse would be a generous understatement: interest mostly hovers between ignorance and neglect, with occasional bursts of irritation or panic.
Even during the current political crisis, British prime minister Theresa May could not seem less interested, while the best one can say about James Brokenshire's leadership of the recent Stormont talks is that his surname seems darkly appropriate.
British oversight in Northern Ireland has a rather sorry history, and a post-Brexit UK has little to offer the region.
We must show our Northern neighbours why we believe they are better off as partners in a shared Irish state
English politicians and taxpayers will likely demand cuts in the subventions upon which it has become economically dependent, and baulk at replacing substantial EU funding.
The Scottish government is already planning another independence referendum and it is hard to see Northern Ireland thriving in even the most blindly optimistic scenarios for “Global Britain” (or “Empire 2.0” in Brexit nomenclature).
Yet there is nothing inevitable about a united Ireland. As TK Whitaker put it half a century ago, the future shape of Ireland will always depend on “agreement in Ireland between Irishmen [and Irishwomen]”.
Unionist attachment to Britain must be respected, and the principle of consent means there will rightly never be any incumbency on unionists to join an Irish state in which they do not feel or see a stake.
But respecting our Northern neighbours also means showing them why we believe in a united future, why we believe they are better off as partners in a shared Irish state than as a forgotten corner of the Brexit tantrum.
Openness and engagement with Europe invigorated our once-insular republic, and we must persuade unionists that their neglected region could walk that same path with us.
The future only lies with the extremes if the centre cannot hold, and it is the often-overlooked centre of northern society that we must engage.
Brexit and reactionary unionism only offer tomorrows based on myths of the past; we must offer one based on the real possibilities of the future.
Devolved governance in Belfast has been hamstrung by DUP arrogance and irresponsibility.
From “cash for ash” to the veto of marriage equality to recklessly backing Brexit, the DUP has refused to govern in the interests of all.
Indeed, grandstanding and squabbling are too often the default for all the major parties.
Many are fed up with the North’s chronic economic and social problems – poverty, unemployment, emigration, segregation – not receiving the attention they deserve. The sectarian politics of the past is a dead end.
Truth and justice
Moving on from history, however, does not mean ignoring it. Many unionists and nationalists have recently shown courage in the search for reconciliation, and all of Irish society must be more active in encouraging and facilitating truth and justice from all sides, a role that the British government – with its tabloid-pandering obsession on avoiding prosecutions of British soldiers – seems unwilling to play.
Any future unity should never be seen as a 'defeat' for the unionist community
The Republic has “legacy issues” of its own too, of course, especially the lingering effects of the excessive church influence that blighted the first half-century and more of independence.
A possible united Ireland requires a non-sectarian modern republic based on equal rights for all citizens, of all faiths and none.
Perhaps most importantly, we need honest and open debate about the logistics and costs that possible unification would involve.
Winning support for a united Ireland – north and south of the Border – will require showing how it will be paid for.
The time for thinking about how Northern Ireland fits into long-overdue debates on regional development, housing and healthcare is now.
This is a project of decades, not years, but we must not follow the Brexiteers’ failure to plan.
Shying away from discussing unification has often left the issue to Sinn Féin.
But the future of the island is a project for all of Irish society, not a route to power for a political party whose Northern electoral strategy too often remains banging the tribal drum in grim symbiosis with the DUP.
Any future unity should never be seen as a “defeat” for the unionist community, or imply that their unionism was “wrong”.
Instead, it should be an entirely new chapter, built together as the agreed best option for the future.
We must listen, reflect and be creative, not simply follow the models of the past: history cannot be granted the last word.
We should no longer stand idly by as Northern Ireland is offered only futures of isolation and separation.
In a globalised world, our little island is too small to accept divisions, and our Irishness should be open enough to encompass all its traditions and hues.
As the centenary of partition approaches, it is time to extend the hand of friendship and ask our neighbours to imagine the new Ireland we could build together.
Dr Christopher Kissane is a historian at the London School of Economics and Political Science, and a BBC/AHRC New Generation Thinker