How does one explain David Trimble's comments about the Republic? It is often forgotten that he, like many other unionists, has roots in the South and a historic sense of siege and displacement. He also tends to let fly when rattled, writes Henry McDonald
Partition has left a deep and lasting psychological scar, not only on the collective mind of nationalists but also upon the community that was meant to have profited most from the division of Ireland in 1921 - Ulster's unionists.
While Irish republicans still refer to Northern Ireland as "the six counties" or "The Fourth Green Field", unionists who are old enough to remember their parents or grandparents recalling the upheavals of the Tan War and the violent geo-political schism of the island, will talk about the "lost counties".
What they mean is those parts of ancient Ulster - Cavan, Monaghan and Donegal - alongside other counties such as Leitrim, which up until partition contained significant Protestant populations. Many of those active in both unionist politics and loyalist paramilitary movements can trace their roots to Protestant enclaves in what is now the Irish Republic.
Alex Kerr, for instance, a former UDA commander and close confidant of LVF founder Billy Wright, once stunned this writer by revealing that his mother was a Donegal woman whose main hobby was Irish dancing.
Another more mainstream unionist with antecedents in the South is the man who last weekend branded the modern Irish Republic a pathetic sectarian state: David Trimble.
There is a Trimble family legend, which Trimble himself has been unable to confirm, that his grandfather's farm in the Irish midlands was burned down during the War of Independence. What is certain is that George Trimble fled to the relative safety of the newly formed Northern Ireland.
George had been a constable in the Royal Irish Constabulary, the force mercilessly hunted down by Michael Colllins's IRA in the 1920s. Grandfather Trimble later joined the RUC and became head constable at Donegall Pass police station in south Belfast.
But Trimble's blood ties to the "lost counties" are not confined to his father's side of the family. His mother, baptised Anne Margaret Elisabeth Jack, was born in Buncrana, Co Donegal.
Moreover, Trimble's maternal ancestors, the Cahoons, have long-standing connections with Donegal; some of them even came across the Foyle into the Protestant citadel of Derry during the siege of 1689.
Perhaps these roots, this sense of siege and historic displacement partly explains Trimble's crass outburst at last weekend's Ulster Unionist Council meeting. For regardless of the reality, many unionists in the North remain suspicious of the South, believing it to be a foreign place from which many of their grandparents and great grandparents were either expelled or forced to flee, like thousands of other Protestants in the second decade of the last century.
History, however, is not the sole factor for Trimble's injudicious comments. Friends and enemies alike agree that there is a petulant streak in the Nobel prizewinner's personality. Although at times he can be the model diplomat, the calm, rational face of unionism, Trimble also has a tendency to let fly when he is rattled.
Witness last weekend's press conference when he was asked on what grounds he based his assertion that the Republic was a sectarian state. His response was to advise the journalist to go and live there: the reporter in question was actually from the South!
Coupled with his impetuousness is a penchant for acting on impulse. When this writer asked Trimble why on earth he had held Paisley's hand in triumph (a man the Ulster Unionist leader has been bitterly at odds with since the mid-1970s) following the Orange march along Portadown's Garvaghy Road in 1995, he offered up a prosaic reason.
"I was having some rather inglorious thoughts at the time. I was thinking 'This is my constituency and I'm not having that fella walking in front of me.' So I thought to myself, 'How I do I make sure he doesn't walk in front of me?' So, I grabbed his hand to keep him in his place. The images were a trifle unfortunate, but there we are."
Trimble is the Roy Keane of Northern politics. Both governments agree that he is as vital to the survival of the Good Friday agreement as Keane is to the prospects of both Manchester United and Ireland.
Man United supporter Paul Bew, professor of politics at Queen's and close confidant of Trimble, enjoys the analogy. "Politically, Trimble has to play at the top of his game most of the time but like Keane sometimes the red mist descends and he says or does things that get him into trouble."
The irony of last weekend's remarks is that while Tony Blair fascinates Trimble, the UUP leader is fonder of Bertie Ahern. And privately, Trimble would prefer to see Ahern re-elected in May. Because Ahern is a man with whom he can do business.
One of Trimble's favourite escape routes from the North's bear pit politics is in the anonymity of London. He relishes being in the centre of a diverse, multicultural metropolis.
Whenever he has a few free hours at Westminster he sets off on his own into the West End, melting into the crowds, strolling towards a bookshop or a record shop. But rarely, if ever, has David Trimble walked around Dublin, which has developed into another multicultural, increasingly secular European city.
When Trimble is whisked into Dublin it is usually in the back seat of a limousine, carrying him to Government Buildings or Iveagh House. Yet if he was able to walk anonymously around the streets, he would rapidly come to the conclusion that the adjective "sectarian" no longer applies - certainly in the capital - to a society that is at best benignly indifferent to events north of the Border.
• Henry McDonald is Ireland Editor of The Observer and author of Trimble - the unauthorised biography of David Trimble, published by Bloomsbury