Ireland-Britain relations have never been better. Underlying dynamics should ensure continued harmony, but for Ireland, Gordon Brown will not be as good a prime minister as Tony Blair, predicts Dan O'Brien.
For most of Ireland's postindependence history relations with Britain were blighted by poisonous historical legacies, reactionary nationalism, imperial condescension and profoundly different worldviews. Happily, these causes of discord have waned owing to deep and fundamental change in both the Republic and Britain.
For Ireland, the passing of time has lessened historical resentments and, in common with the rest of western Europe, drum-beating nationalism has become an embarrassing anachronism. Integration into the European polity has widened perspectives, and because the EU is a union of laws, it has had a levelling effect on the relationships among its participant states regardless of their relative size.
A more balanced economic relationship has also evolved. Britain has declined in relative importance for Ireland, while the rapidly growing Irish economy has become more important for Britain (Ireland is now the UK's fourth largest export market, and the UK Ireland's second, recently pushed from top spot by the US).
Changes in Britain have been as significant in the bettering of relations. Those generations imbued with the mindset of empire have largely passed on and a new consensus has emerged that the subjugation of other nations in the past is a blot on Britain's history, not a source of pride. A changing ethnic and cultural profile - although not without its own problems - has generated a genuine cosmopolitanism in domestic and international affairs.
These changing values and perceptions of interests in the Republic and in Britain were crucial in dealing with the North's troubles. In our "post-nationalist" times, the central and shared interest has become the quality of the North's governance, not who governs it.
Relations between modern democratic states in which power is widely diffused are determined far more by their context - the dense webs of economic, social and political connections that exist - and far less by individual agency. But leaders still make a difference. As such, the passing of the British premiership from Tony Blair to Gordon Brown today can be expected to have implications for Ireland-Britain relations.
As always, the North will loom large. Despite the restoration of devolved legislative and executive institutions, further crises are all but inevitable. The DUP's erratic fundamentalism and Sinn Féin's obsessive irredentism should see to that. Brown, even if he chooses to deploy his prime ministerial authority as liberally as did Blair, is unlikely to be as calming. He has neither the outgoing leader's patience nor his gentler powers of persuasion.
Although Blair was willing to expend his energies on major global issues, he did not see smaller matters as being beneath him. This was unusual in such a powerful figure. Brown is far more typical. He brushes aside those issues he considers trifling. Given that he cannot always hide his irritation at what he sees as petty parochialism among his co-nationals in Edinburgh's parliament, he will not concern himself excessively with squabbles in Stormont.
Nor is he likely to be as well disposed to Dublin. Leaders of larger countries prefer photo opportunities in the White House rose garden and imparting their wisdom to the UN's general assembly to the tedium of summits with small countries. This dynamic, which bedevils relations between big and small states, was absent during Blair's premiership. It should reassert itself under Brown's.
This would be less than helpful if any crisis in the North were to lead to the collapse of devolved government. The "Plan B" option envisages an intensification of engagement between the governments. But Brown by inclination would be tempted to revert to a more traditional unilateralist approach, less willing to consult Dublin before he acts, and less willing to pay heed to Dublin's input when he does choose to consult.
The handover of power to Brown will have implications not only for Ireland's bilateral relationship with Britain, but also for relations in our shared European multilateral space. Britain's size and proximity exert an inescapable gravitational pull on this island. Should it drift away from the continent, Ireland would inevitably be disturbed in its European orbit.
There is reason to believe that such a drift could take place on Brown's watch. British public opinion is as sceptical as ever of EU membership and there are dwindling numbers of prominent figures and organisations willing to making the case for engagement.
This is unsurprising. No country can easily transcend its history. From the end of the Hundred Years War more than half a millennium ago, our neighbouring island sought to limit its continental entanglements. Centuries of semi-detachment have left their mark.
More recent history explains the further waning of the enthusiasm for engagement. The case for participation in the European project in the 1960s and 1970s was founded first and foremost on the clearly superior performance of the major continental economies.
Much has changed since. From a position in the 1970s of decades of relative decline, Britain has outpaced France, Germany and Italy on most economic measures since the 1990s. No one personifies Britain's new-found belief in the superiority of its economic performance than the man who claims most credit for it - Gordon Brown.
How will Britain's stance in Europe change under him? This remains something of a mystery owing to the care he has taken to avoid setting out his stall on foreign matters. But there are straws in the wind. As chancellor for 10 years he has rarely given the impression that he considers meeting his fellow EU finance ministers anything other than a chore. He also tends to be dismissive towards their ways and looks to the US for policy ideas.
More recently, the debate over how to reform the union's ground rules suggested, at the very least, that he sees no case for deeper integration. The original constitutional text, which was rejected by French and Dutch voters in 2005, was agreed by Britain three years ago. Blair said then that it was a good deal for his country. Last week he fought to prevent many of its most significant elements being included in a new draft. It is hard not to see Brown's hand at work.
Economic, political and social trends in Britain suggest that, if anything, it will become more detached from Europe. Blair, who had a genuine desire to bring Britain closer to the EU's heart, worked against those trends. Brown is unlikely to do the same.
Strong relations with Britain and full engagement with Europe are both vital national interests for Ireland. If Britain and Europe draw apart, Ireland may be forced to choose between them. If this comes to pass, or if co-operation on the North becomes more difficult, nostalgia for the New Labour era will quickly take hold. It may be that with Blair's passing, the best of times in Ireland-Britain relations have passed too.
Dan O'Brien is a senior editor at the Economist Intelligence Unit, London