Ireland enter the World Cup burdened by unprecedented levels of expectation, but for skipper Brian O'Driscoll the hopes of an eager nation are well justified.

Widely touted as genuine contenders to lift the Webb Ellis Trophy for a first time, even England's World Cup-winning captain Martin Johnson is backing Ireland to tighten northern hemisphere control of the tournament.

New Zealand's air of invincibility has been pierced by an erratic Tri-Nations, defending champions England have struggled since 2003 and hosts France have failed to convince despite winning the Six Nations.

Australia can never be counted out while the feeling that South Africa are on the brink of something special is unavoidable, but Ireland deserve to be considered in such company.

Had they not been drawn in the 'Pool of Death' alongside France and Argentina, with a possible quarter-final against New Zealand waiting, their prospects would have been even rosier.

But despite the tough passage to the final that potentially lies ahead, O'Driscoll insists it is Ireland's rivals who should be concerned.

"Why should we worry about who we will play in the tournament? I think we will be giving plenty of the top sides sleepless nights hoping they will avoid us," he said.

"Winning the World Cup is every player's ultimate goal. I'd simply love to be in that position - to do what Martin Johnson did and lift the cup.

"But there is a long, long road ahead of the Ireland team before we could get that chance. I'm certainly looking forward to this World Cup.

"Another northern hemisphere side will hopefully win it again - I'd love it to be Ireland.

"We have to be one of the top four or five sides who can win it. This is one of the strongest Irish sides I've played in.

"New Zealand are favourites again but I always believe any team is beatable.

"I don't think we need to be worried about playing anyone. We'll give the other top sides sleepless nights."

And it is O'Driscoll himself who will be the greatest cause of insomnia for Ireland's rivals.

Coach Eddie O'Sullivan may have been blessed with arguably the nation's finest generation of players, with some dazzling threequarters complimenting a robust pack, but O'Driscoll remains the spearhead.

A stunning hat-trick against France in the 2000 Six Nations marked the 28-year-old's arrival as a major Test force and he has been regarded as one of the world's finest centres ever since.

He has the pace and power to open gaps and finish chances and the handling and vision to unpick defences.

As a leader he remains Ireland's figurehead and talisman to the extent O'Sullivan questions the side's ability to win without him.

A hamstring problem forced O'Driscoll to miss the heart-breaking 20-17 defeat by France in February and O'Sullivan believes that absence exposed how important he really is.

"We missed the best international centre in the world - no-one would argue with the fact Brian O'Driscoll was a loss against France," he said.

"Losing O'Driscoll is hard, there's no getting away from it. I don't think any country in the world could replace him if they had to.

"I knew that no matter how well we prepared for France, there wouldn't be that edge to our attack and defence without him.

"There's no point pretending we don't miss him."

O'Driscoll's influence in the Irish camp is total with no other team in Test rugby relying so heavily on one man for leadership and self-belief.

Even the mighty Paul O'Connell, who deputises for O'Driscoll when the Leinster centre is injured, cannot lay claim to having the same authority.

But appreciation of O'Driscoll is not universal with Bob Dwyer, a respected retired coach and the mastermind of Australia's 1991 World Cup triumph, aware of several shortcomings.

Dwyer worked with O'Driscoll during a Barbarians tour two years ago and ended their time together with mixed feelings.

"I didn't get the impression he was the most coachable of players," he said.

"Why did I think that? There was a smugness about him, a lack of modesty, too. Even the great players have to be willing to learn, but Brian didn't seem too keen.

"I got the impression he thought he knew it all and didn't need to listen to a coach.

"In my view, Brian O'Driscoll is a great player, but he could be an even greater player if he was prepared to listen and learn. Even the best players can benefit from that.

"His strengths are his flaws. His lightning acceleration and outside break is a very strong part of his game.

"But unless those qualities create the ultimate advantage they bring a strong disadvantage, which is that he gets tackled going sideways.

"What that also means is that he has used all the space those outside him need to play in."