I’ve come back from three recent trips to Ireland marvelling: this is what a grown-up country looks like. A giant, potentially divisive issue comes along — the sudden prospect of a united Ireland, a republican dream since long before Irish partition in 1921 — and instead of treating it as a winner-take-all, biff-bang argument as in certain countries one could mention, almost all Irish seem determined to move slowly, seriously and fairly. How to reassure mostly Protestant Unionists in Northern Ireland, who for generations have identified as British? I’ve seen a hall full of Irish people applaud a woman urging them “to be open and inclusive to Unionists”. The 4.8m Irish in the Republic and 1.9m in Northern Ireland still face a scary decade. Irish unification could revive the north’s violent Troubles. But blessedly, most Irish people realise that. Here’s a rare case of a country learning from history.

English politicians and Northern Ireland’s Unionists have done more to unite Ireland in three years than Irish republicans managed in a century. “Brexit has catapulted this issue forward,” says Padraig ó Muirigh, adviser to the republican Sinn Féin party. “There is a real sense that we’re living in historical times.” Last month, Boris Johnson agreed to place the de facto future border in the sea between mainland Britain and Northern Ireland. That put both Irelands in one economic zone, and showed Unionists that the English nationalist Conservatives considered them expendable. In fact, some Unionists feel they’ve had more understanding from the Dublin government.

The 1998 Good Friday Agreement stipulates that if both sides of Ireland vote in a referendum to unite, it will happen. That could be soon. Next year a hard Brexit, or a Scottish vote for independence, could encourage Northern Ireland to escape the British mess. Then, the 2021 census would become the first ever to show self-described Catholics — who traditionally back Irish unification — outnumbering Protestants in the north.