IT is worryingly close to 25 years since a work assignment first took me across Ireland.

Memories of the time are hazy but I do recall that most of the houses along the way seemed half-built and the most common road signs warned of loose chippings or a temporary road surface ahead. When I got back, someone asked me what the place was like. "Nice enough" I replied. "But it will be a lot nicer when it's finished."

In which light, a quick blast across the Emerald Isle last weekend made for an interesting comparison. For the most part, Ireland is indeed finished now, but I'm not sure that it is a lot nicer. The main routes across the country seem to bypass all the towns and villages that once added interest to the journey, while most of the houses look like the sort of bolt holes East End gangsters would knock up in Marbella.

In short, it's not all that obvious that the easy money of the Celtic Tiger years was such a good thing for Ireland. With hindsight, much of that money turned out to be as illusory as the faux marble bathrooms and plaster porticos that are the accessories of (very bad) choice at these improbable miradors but, even as Ireland recovers from its financial collapse, there are some pretty nasty blots across its landscape.

Yet, in sporting terms, the legacy of the boom years does not seem too affected by the bust that followed. Ireland will head to Twickenham on Saturday with confidence bolstered by back-to-back RBS 6 Nations wins over Scotland and Wales, their match with England made to appear all the more momentous by the fact it takes place straight after Italy and Scotland, both winless and dispirited, have served up a contest that, in championship terms, is little more than a warm-up act.

The contrast between Irish and Scottish fortunes in rugby over the past 15 years demands in-depth analysis, but it will be an incomplete account that fails to mention the great dollops of good luck Ireland have enjoyed in terms of natural talent. In the past, Ireland's once-in-a-generation players used to come along, roughly speaking, about once in a generation; since the turn of the millennium they have been turning up at a rate of about one a year.

I have a long and rather embarrassing back-catalogue of articles under my name, all of them predicting why Ireland's golden era was about to end. I'll probably knock out another one before too long, an earnest explanation of why Ireland will go into free-fall when Brian O'Driscoll retires at the end of this season. They'll probably respond by unearthing another centre who is just as good, if not better.

Yet, as the Irish have pulled a succession of rabbits out of their big green hat, there has at least been one element of continuity that seems central to their success. They have not just churned out great players, but great leaders. As Munster turned themselves into a European force between 2000 and 2006, they had the great meat-plate hands of Mick Galwey and Anthony Foley on their tiller. When Leinster took over as the Heineken Cup's most powerful side, they had Leo Cullen imposing his will. And O'Driscoll wasn't too untidy in the role either.

Above them all, though, head and shoulders if you like, rises the great, golden cupola of Paul O'Connell's cranium. Early in his career, O'Connell was cursed with the tag 'the next Martin Johnson' but, if he was slow to meet those expectations, he has more than done so now. Whether in the colours of Munster or Ireland or the Lions, O'Connell is one of the greatest players of the modern era. And, arguably, the greatest leader.

When O'Connell was ruled out of last year's Six Nations, it was suggested in some quarters that Ireland would be better off without him. The argument was that Ireland had to move on from a game based on old Munster forward values of graft and grunt and menace. They needed finesse and O'Connell could not provide it. When Ireland finished fifth in the table the voices from those quarters fell strangely quiet.

And yet, as I said, O'Connell is just one of a number of great leaders who have emerged in Ireland in the professional era. Even those who have not worn the armband more than a handful of times have still managed to galvanise their provincial and national teams through force of will and strength of character. Irish colleagues cite such figures as Peter O'Mahony, Peter Stringer and Rob Kearney as players who have had that impact over the past 10 years.

How would I respond if they asked me the same question? I'd probably mention Jason White in the context of Scotland, and speak of Al Kellock at Glasgow, but then I'd almost certainly dry up. Sure, lots of very good players have captained Edinburgh, Glasgow and Scotland in that time, but it's a struggle to think of any who have had that extra charge of leadership, the particular abrasive quality grand slam skippers Jim Aitken and David Sole brought to Scotland, and was gifted to other countries by figures like Sean Fitzpatrick, John Smit, Johnson and O'Connell.

For the most part, and for want of a better term, Scotland's recent captains have been company men. They have had a talent for obedience. It is hard to imagine any of them standing up to a coach, telling the fellow he is talking nonsense and that the team would be doing things their way instead.

Yet that boldness is exactly the quality Scotland need right now. Only the other day, Ian McGeechan talked of the feeling of drift around the Scotland team, the lack of a sense of purpose.

In the dressing room and on the pitch, a strong individual can do far more to arrest that slide than any coach ever could.