There is no logical reason why the political leaderships of devolved governments, even of widely differing persuasions, should not make common cause in pitching their case to central government. Nationalists and unionists can do so in Northern Ireland in the context of the devolved Assembly without threatening their respective constitutional positions, and, mutatis mutandis, so can the two devolved administrations in Holyrood and Belfast to mutual advantage.
The visit on Monday to Belfast of Scotland's first minister, the SNP's Alex Salmond, his first foreign trip since he took over as leader of a minority administration, marks an important symbolic first step in what can become a fruitful dialogue that can strengthen the hands of both Mr Salmond and Dr Paisley. To suggest as the Ulster Unionists did that the meeting represents some kind of "nationalist trap" is patent nonsense.
The two men signed a joint statement pledging to work together on tourism, higher education, transport and the pursuit of a cut in corporation tax. They intend to involve the Welsh administration once the shape of that organisation becomes clear. Mr Salmond is keen to use protocols allowing for joint approaches by ministers from the devolved parliaments in their dealings with Westminster - indeed, on Monday the British environment secretary, David Miliband, hosted a meeting with representatives of the devolved administrations.
As part of a "fresh start" in the relationship with London Mr Salmond also sees a welcome potential for developing the role of the British-Irish Council and the opportunities for bilateral contact between Scotland and the Republic, which he has long held out as a role model for small independent states in the European context.
That European context does, however, complicate one of the key issues on which they have agreed, their desire for a corporation tax pitched at the same 12.5 per cent level as the South. "One thing is for sure," he argued in Stormont, the North's special pleading notwithstanding, "we would be more successful if we were pressing together than we would if we were pressing separately."
But the mood music from chancellor Gordon Brown's treasury is not good. Even were he amenable, EU competition rules regard differences in corporation tax levels within states as a form of prohibited state aid. The crucial exception is where regions exercise a genuine degree of fiscal autonomy, which neither Belfast nor Holyrood do. In the longer term, however, that carrot of increased fiscal devolution may provide a substantial imperative for a common cause between the two administrations.