In a sense, Foster probably couldn't avoid going down this road as he confesses to a fatalistic attraction for this period of recent history. "I mean, the last 30 years seem to me to be fascinating. The more I looked at it the more I thought this is a huge subject . . . and it struck me that it's not just a cheerfully rising graph of prosperity, and the North being settled and all the rest of it. It's a series of interconnected crises in some ways, and it's also a series of interconnected liberations."

For history geeks, the merging of a divisive historian with a period in our history which has shown phenomenal change resisting easy reduction could be a marriage made in heaven. Foster has always been one of our more interesting and stimulating historians, and is well used to having the word 'revisionist' thrown at him in the most pejorative sense. Despite this he has a clear sense of his position: "I think of myself as one of a generation of historians who have perhaps written more publicly and addressed more contemporary, and sometimes more provocative subjects. And perhaps that's a contrast to the slightly more removed stance of the previous generation when academia was a slightly different business, so to speak." He speaks of the "two very opposing strains of interpretation of what the economics of the last 30 years meant", and the book bubbles and fizzes with all the intellectual energy required to express dynamic cultural change.

One of the book's most successful chapters concerns the development and decline of Haughey's Fianna Fail. It's made all the more impressive because it manages to lend a freshness to events which are already in the public domain. And it stems from Foster's urge to examine "the whole Fianna Fail version of history", particularly in regard to their stated claim to being sole creators of a successful economy.

Foster stops just short of calling their version a myth. Central to this is his conception of Haughey "and the astonishingly total nature of his disgrace" which he sees as akin to "something from Trollope or Balzac". Indeed Foster chooses the conceit of treating the narrative of Haughey's career as if he were the hero/anti-hero of a Balzac novel. When he speaks of Haughey it is with a mild disdain tempered with a huge inquisitiveness. He refers repeatedly to Haughey's "smoke and mirrors" job, but qualifies this with his claim that "it's by no means just a denunciation. He's much too interesting for that."

Foster though is very definitive about Haughey's legacy. "The closer one looks at his extraordinary, and, in many ways squalid, career, the less he actually did. And for all his claims for having begun great things, the Peace Process, the economy, the less it seems to have been the case.

And when he did attain power he did surprisingly little with it. This is not unconnected with the question of financial corruption which is also one of the major themes of the chapter on Fianna Fail." He points out that it wasn't Haughey who came up with the Tallaght Strategy, nor was it Haughey who created the IDA. He also trashes the myth that Haughey attracted investment into the Financial Services Centre, alluding to the fact that "the guidelines for that had been traced out before". Haughey's hubristic fall from grace, fuelled by an "intrinsic corruption" even had its own narrative denouement of sorts. "I do make the point that when he was surgically destroyed in cross examination at the 4McCracken Tribunal, the senior counsel who destroyed him was a figure whose grandparents had been founding members of the old Fianna Fail, and I've often thought that sheer icy anger with which he was treated was as much because of the historical tradition he had betrayed in terms of somebody who came from the old Fianna Fail ranks, as because of the immediate questions of financial corruption in democratic politics."

Foster stresses that he doesn't like examining history or politics in terms of personalities, but admits that sometimes this is unavoidable. This is particularly true in the inevitable comparisons between the "Napoleonic" Haughey, and the intellectual Garret Fitzgerald, "who in some ways is a hero of this book . . . I say that completely unrepentantly." A man Foster admires for his "realism and sophistication".

Foster is an admirer of another hero of sorts, a man he does believe has lent the country a certain respectability. "I admire Bob Geldof because he's extremely clever, which I know is not always admirable, but I do think he is brilliant. I admire his fantastic articulacy. If you want to talk about being good for Ireland, when I hear him marshalling his arguments in a way that any Harvard academic would be proud to be able to do then I do feel absolutely that this is good for Ireland. I think he's been . . . and I hate this word . . . an 'ambassador', but he has presented uncompromising arguments from a very intelligently argued place. I think for all the grandeur of the world that he moves in, and influence he can have, he hasn't sold out on what he thinks is important." Foster's admiration extends even to Geldof 's personal life. "I also think he has handled a traumatically and tragically famous life with immense dignity. I think if that's representative of the New Ireland, I think he's an ornament to it. This may make me sound sentimental, but I think I would have to stand by him."

I ask him about his attitude to Bono and he laughs, and then sighs, like someone contemplating the predictable behaviour of an errant child. "Again, he's somebody who just hasn't devoted himself to frivolity." He pauses for a moment: "Although he may take himself rather more seriously than Geldof does. I still think that he's used immense wealth and fame and influence to much better ends than a lot of rock stars. And I think he's very politically savvy as well, as are a lot of politicians who try and create photo opportunities with him." I tell him about Bono being snubbed by the Canadian prime minister at the recent G8 Summit, and Foster can't help himself. "Oh, that's very funny."

His views on the North are also strong and he believes the effects of the last few years have been to solidify partition and to entrench the border. "When I look at what's happening, it's very nice that they're not killing each other, but I think to myself, Paisley and McGuiness represent the two elements that did most to destroy power sharing in 1973 to '74, and here they are running what Seamus Mallon epigrammatically called 'Sunningdale for slow learners'. Why did they need 30 years and 3,000 deaths to realise that this is what makes sense?"

Again, he betrays that subtle disdain, particularly for the south's now condescending attitude to the North. "It's just so emblematic that in the heel of the hunt what happens is they throw money at the problem. Bertie Ahern makes hundreds of millions available as sweeteners and inward investment into the North to persuade McGuinness and Paisley.

Go away and leave us alone, here's some money."

But in keeping with his dual academic role as a History and English faculty member at Oxford, Foster is also eager to examine the "cultural energies" of the last three decades, and the transformation into a nation of novelists "writing novels with such panache, and such success, and command" responding, particularly in the case of Dermot Bolger ("a very important figure") to "the sense of country and city coming into a new relation with each other". Foster also goodhumouredly points that he predicted that Anne Enright would win major literary awards.

"Maybe I should set up as a soothsayer." Whatever about that, his book is rigorous and incisive and is worth reading alone for the hilarious fusion of a literary reference and the image of a hogtied Ben Dunne being carried from that Florida hotel.

Foster left Ireland in 1974, but is prepared for the predictable criticism that this book is written from an outsider's perspective. He visits at least once as month, and he sees himself as "fairly well equipped to observe the transformations over that 30 year period. Those of you who were in a sense born into it and grew up in it, it probably doesn't seem so astonishing to you. But I can assure you, if you were as old as me you'd be rubbing your eyes."