BREXIT, and the negotiations to come, are a revival of old histories: a power struggle between England and continental Europe.

While our islands are physically adrift, politically Britain was overrun by the Romans, Angles, and Vikings and then endured dynastic rivalries with France and Germany. Within the history of Britain’s relationship with Europe, Scotland and Ireland also have a distinct tradition of appealing to Europe to balance English dominance.

In different circumstances those old national rivalries are repeating themselves. Come next March the governments of Dublin, Edinburgh, and London will face a harsh reality: they will have 26 EU opponents in a process that brings threats too numerous to list.

The Irish Government, which has its economy and peace process now awkwardly straddling the EU and Britain, is approaching Brexit with trepidation. The Tories have no plan, so the Irish need one of their own – and as many allies as they can find.

Enter stage left Nicola Sturgeon, and the potential of a renewed Celtic Alliance. The interests of the Scots and Irish governments for Brexit – as little disruption to open trade and movement as possible – align.

This could, officials in both governments hope, provide a counterweight to the arrogance of Tory ministers’ determination to chance their way through European diplomacy.

Sturgeon’s ongoing visit to Dublin included meeting the Irish President and Foreign Affairs minister yesterday. Today she will address the Seanad. The various formalities are as if Sturgeon already represents an independent state.

Scotland’s status has undoubtedly climbed up the Irish agenda since June. Taoiseach Enda Kenny spoke at the EU leaders’ meeting of Scotland’s vote to remain. Fianna Fáil leader Micheal Martin called for Ireland to support fast-tracking an independent Scotland to EU membership. Sean Kelly, the lead MEP for governing party Fine Gael, said that sympathy for an independent Scotland had shifted due to Brexit.

While Sturgeon’s tour of wind farm projects, business meetings, and university campuses can be seen as a standard promotional trip – it is happening on top of shifting tectonic plates. The Scottish Government, in its low key meetings in Paris, Berlin and elsewhere, has an independent albeit embryonic foreign policy with Europe for the first time in over 300 years. Its main priority is to pave the way for Brexit talks.

Then Kenny and Sturgeon face a similar dilemma. Both want a "special status" from any Brexit deal – but both have to be prepared for rejection from EU negotiators. The Irish, unlike Scotland, at least have a pledge from Westminster to oppose any "hard border" in the north of Ireland. Yet what would happen to cross-border trade on Ireland if the UK is out the single market remains hazy.

Kenny, like Sturgeon, has raised the prospect of ending the chaotic incompetence of a Tory Brexit with a referendum. That route would mean a "border poll" on unification. This is not a strategy Irish politicians have planned for or would relish (Sinn Féin aside), but it is now a possibility.

Sturgeon, with less sympathy from Westminster and without Ireland’s full EU representation, can attempt to replicate any special Northern Irish Brexit deal for Scotland. Ireland, keen for the softest of Brexits, could be Scotland’s top ally among the 28 states that negotiate the final deal. Yet there should be no illusions over how neighbourly sympathy translates into political sacrifice. Ireland’s economy and Northern Ireland, naturally, are the priority for Irish politicians.

In law a devolved government – as the neutral-to-sceptical statements from EFTA countries about Scottish membership have shown – is not treated like a sovereign state. As facts stand, that limitation – combined with Westminster intransigence – may well kill off aspirations to protect Scotland’s place in Europe without a fresh independence referendum.

Yet in those circumstances developing a stronger Celtic Alliance will not have been in vain. Scotland, on the verge of independence, would have to confirm intent to remain within the EU or seek the similar benefits of EFTA. Irish support at that point would also be mutually beneficial.

This revived combination of Scottish, Irish and European interests repeats tales of history.

It was the Vatican that Scots nobles addressed for protection in the Declaration of Arbroath. The Scots repeatedly allied with the French, while the French tried to exploit their English rivals’ weakness through supporting the Jacobites.

Likewise, Ireland turned to European allies to support its political causes – from the failed rising of 1798 through to the events of Dublin 1916.

The modern European battlefield is the negotiating table, where the long, lingering shadow of British imperialistic arrogance seeps into the Tory approach to Brexit. A strong Celtic Alliance is exactly what is needed as a counterweight.

If the Tories remain determined to steer towards the looming iceberg, and a fresh referendum is needed as a lifeboat, it will be a comfort to know we are not alone.