Mary Dejevsky: Sell Ulster, and earn a peace bonus

Which government of the Irish Republic has not longed to go down in history as the one that brought the Emerald Isle back together?

How much longer must the British Government go on trying to expiate the sins of our fathers and forefathers in Northern Ireland? As details were revealed this week of how the involvement of a Catholic priest in the 1972 Claudy bombing was hushed up by British ministers, in collusion with Church leaders and the Royal Ulster Constabulary, you could sense a weariness across mainland Britain and a public opinion steadfastly unmoved.

The non-response was in sharp contrast to the passions revived across the water. With the priest concerned, Father James Chesney, dead since 1980, there was not much anyone could do beyond rage on one side and breast-beat on the other, but the Northern Ireland Secretary, Owen Paterson – barely three months in the job – duly expressed the Government's "profound sorrow" for not having investigated the priest at the time, even though, both then and now, it is hard to fault the decision.

The Claudy apology was but one instance of Northern Ireland intruding on the mainland's consciousness this summer. The season began with the report on the Bloody Sunday killings (12 years in the compiling) and David Cameron's oh-so-elegant speech of contrition in Parliament. You might even draw a connection: the minister's regrets over Claudy as a small olive branch extended to Ulster's Protestants, following complaints that Catholic deaths had been investigated more assiduously than theirs. Or you could see it as a sop towards Loyalists a month before Pope Benedict's visit to Britain.

It is not necessary to interpret the Claudy apology in this light, however, to appreciate the glaring gap between public sentiment there and here. The peak of the Ulster marching season came and went, fraught with brinkmanship there, almost ignored here. Sundry bombings and attempted bombings have taken place, ascribed soothingly to "dissident republican groups" – meaning nothing to worry about. And the BBC got itself into a splendid twist about whether Derry or Londonderry would be the UK's first Capital of Culture in 2013; they used both on air.

More and more, Northern Ireland is another country. So perhaps it is time for Westminster to accept this and even gain some benefit from it. Granting full independence might be one option; there are successful countries with smaller populations than Northern Ireland's 1.7 million – Estonia, for instance. But with a population that defines itself almost entirely by its loyalty or not to the UK, the likelihood of this happening voluntarily is zero. But how about a sale – or even cession – to the Republic of Ireland?

Sales of territory by countries strapped for cash or shifting policy priorities have precedents, most notably Thomas Jefferson's purchase of Louisiana from France in 1803 for 60 million francs, or the US acquisition of Alaska from Russia in 1867. Whether the Irish Republic could afford to pay as much, or indeed anything at all, for the six northern counties might be doubted. Dublin's own economy is not in the best shape and recent austerity measures seem not to have yielded as rapid a success as had been hoped.

Against this short-term calculation, however, stands the dream of a united Ireland. And which prime minister or government of the Irish Republic has not longed to go down in history as the one that brought the Emerald Isle back together? Is realising the dream not worth a relatively small mortgage on the united country's future?

A sale would be the mercantile option. In fact, though, Westminster could afford to give Northern Ireland away and still come out ahead. Its net cost to the Exchequer is put at £9.3bn for the financial year 2008-9 – a greater per capita cost than for Scotland or Wales. Even if that expense were projected to remain static, rather than rise, the savings alone would make a nice dent in the UK's £900bn national debt within 30 years.

Plus the Republic would gain some of the most lavishly funded infrastructure that exists in the UK. Nowhere else has had a fraction of the attention or public investment that has gone into housing, roads, schools and hospitals of Northern Ireland. The Dublin government would not be in the position of West Germany's government in 1990, having to absorb a dilapidated and bankrupt state a third of its size.

Only in one respect, security, would it be taking on a liability. Of course, if the whole population of the North could be persuaded that transfer to the Republic of Ireland was in their interests, then the security problem would be near to a solution, too. It would be more realistic to assume, however, that it would be simply turned on its head, with the Protestants, now the rebel minority, and doubly infuriated because their will had been overruled.

But being a religious or ethnic minority in Europe in this day and age is not what it was a century ago; nor do the North's Protestants, as they well know, enjoy the privileges they once did. In the European Union, minority status brings statutory recognition for education and culture, guaranteed representation and funding. With the Protestant majority in the North smaller than it has ever been and fast-vanishing, assent to unification may anyway be just a matter of time. Would it not be in everyone's interests to hasten it along, and allow Britain to bask in a rare moment of magnanimity?

It could be objected that if the UK is open to selling or ceding territory, why start with Northern Ireland? Surely it would make sense to deal first with the more acrimonious disputes, such as the Falklands or Gibraltar. But culture and language are far bigger obstacles here than they would be with Ireland and, for London, relinquishing either would be seen as a diplomatic defeat. There is no such difficulty with Northern Ireland, whose transfer to the Republic would make cultural, demographic and geographic sense. At once, the security of Britain and Ireland would be enhanced. The biggest bonus of all, though, would be that relations between Britain and Ireland, as sovereign states, would become normal in a way they have never been in recent times.

m.dejevsky@independent.co.uk