Irish-British relations are about to undergo their biggest change since the 1970s, and arguably since Independence. The two states will remain close after Brexit, but they are about to take fundamentally divergent paths, and that parting of ways will alter the relationship profoundly. Douglas Hurd once observed that in joining the European Economic Community (EEC), Ireland effected "a decisive shift away from the embrace of Britain". But of course, EEC membership was a step taken in tandem with London. Paradoxically, what was portrayed as a break with Britain also brought Dublin and London closer, and contacts developed in Europe were to assist the peace process in its early days.
Brexit will be a far more significant rupture, and already there are signs of new strains in the relationship. Differences of approach over the deadlock in Northern Ireland, which have passed beneath the surface for months, came into the open this week, when Minister for Foreign Affairs Simon Coveney insisted there could be "no British-only direct rule" if the Stormont institutions were not re-established. In a blunt response, the Northern Ireland Office said the British "would never countenance" joint authority. Both sides have sought to play down the differences, but it seems clear that tensions over Brexit are leaking into their involvement in the North. Also colouring the picture is the Westminister deal between the Conservatives and the DUP, which has forced all parties to dispense with the pretence of British disinterest, as well as Dublin's natural sympathy with those, including an overwhelming majority of nationalists, who opposed Brexit and seek the solution closest to the status quo.
While Dublin welcomes London's reassuring pledges on its chief concerns – the Border, free movement of people and the peace process – there is growing exasperation at the British failure to show how it proposes to reconcile some of its contradictory aims. In particular, how can the British possibly leave the customs union and expect a hard Border not to return in some form? With Anglo-Irish relations now overseen by two men, Taoiseach Leo Varadkar and Coveney, who came of political age in the post-ceasefire era, the Irish side's tone has sharpened noticeably. Last month, Varadkar remarked that Dublin was "not going to design a border for the Brexiteers".
The inescapable impression is of two friendssteadily growing apart. For 40 years, Dublin has looked to London as its closest ally on the issues that mattered most. Now it finds itself sitting across the table, with the EU27, seeking to position itself with new alliances for a new era. Yet the Irish and the British will still be seeing a lot of each other, of course. A strong working relationship will be in both countries’ interests, and they must do everything they can to ensure that the current tensions do not leave a lasting divide.