Michael Vaughan was in an unquestionably peevish mood during this week's first Test. Any pleasure he might have taken from a record-equalling sixth century at Lord's was diminished by the carping about his form that preceded it, while the unsatisfactory finale to the match gave him few causes for good humour either. As the Lord's Test petered out into a draw for the fifth time in a row, England's killer instinct once again had to be called into question, and nothing riles Vaughan more than the suggestion that his charges are a soft touch.

You could see him trying to make things happen on that final afternoon. Like a chainsaw operator with a faulty choke, Vaughan tugged and tugged at the ignition cord, pressuring New Zealand's brittle batsmen with packed cordons and aggressive lines of attack. He even called for the new ball the instant it was available, but nothing he could do could spark his unit into life. Comparisons, as they say, are odious, but four years ago, as everyone in the camp is aware, New Zealand were routed 3-0 in a series that set a benchmark for the 2005 Ashes. It's hard to imagine the class of 2004 missing their cue as England did at Lord's on Monday.

The opportunity undoubtedly presented itself. With Brendon McCullum in hospital, New Zealand's defences were manned by a strokeless debutant and an out-of-form allrounder with a self-confessed phobia of a certain left-arm swing bowler. Sixty-five overs remained in the day, and the lead was a mere 78 with five wickets in hand. It was a situation reminiscent of the Headingley Test four years ago, when Matthew Hoggard and Steve Harmison grabbed four wickets in 18 balls in the dying overs of the fourth day's play, to transform England's fortunes in a game that seemed beyond salvation.

Nothing of the sort happened this time around, however. In fact, Jacob Oram's counterattack was so speedy and successful that, had the match gone into a sixth day to make up for all the time lost to rain, England might well have found themselves in a spot of bother. Vaughan actually scoffed when he was quizzed on this very point by a journalist after the match - he denounced such a scenario as "ridiculous" - and yet when England were last asked to chase a total in excess of 250, at Hamilton back in March, they tripped over their feet in their haste to make the kill and ended up losing by 189 runs.

All such thoughts and more are bound to be cluttering Vaughan's mind as he moves north to Old Trafford - a venue that is arguably the paciest in world cricket today, and should therefore play into the hands of England's quicker bowlers. England expect to win, because they are programmed by precedent to do so against the Kiwis, but beneath the scowls and away from the cameras, Vaughan will acknowledge that his charges came up short at Lord's.

Regardless of their final-day failings, they bowled poorly in helpful conditions on the first afternoon, then batted without resolve when the sun deigned to make an appearance on Sunday. The difference in weather patterns from first day to fourth was so stark that, had England played to their potential across the two innings, New Zealand could easily have been bowled out for 150 and conceded 400 - a 250-run deficit before Oram had even got going.

There is, however, one unequivocal positive that England will take out of the Lord's Test, and it is possibly more crucial than a win. By restating his credentials with a century of such simmering intent, Vaughan has nipped in the bud the debate about his own place in the side. If, on Friday, England name the same XI that played at Lord's (and only a late injury or a pitch-inspired recall for Chris Tremlett will persuade them otherwise) they will have been unchanged for four matches in a row - a run of selectorial clarity that hasn't been matched since the start of the 2005 Ashes.

England's presumptuous attitude towards New Zealand disguises the fact that the bare bones of a competitive team are being pieced together, but no piece is more crucial than the captain himself. Next week's second Test marks the anniversary of Vaughan's recall to the England team, which he made memorable with that emotional century against West Indies at Headingley. But it is an indication of the progress he has made in the past 12 months that all discussion about his role in recent months has revolved around his form - not his fitness or his age.

After four knee operations and as many aborted returns, no one truly imagined that Vaughan, 34 next birthday, would still be in the role five years on from his first series in charge against South Africa. But he is, and to judge by his statistics, he is every bit as influential in his second coming as he was first time around. In 13 matches since May 2007, Vaughan has racked up 990 runs at 43.04, which is virtually identical to his career average of 42.96 from 77 games. His centuries still come at just over one every four games, and anyone who witnessed his second-innings hundred against India at Trent Bridge last July will attest to his enduring style and grace.

But the crucial thing about Vaughan is that he is there at all. His run-scoring as England captain will never hit the heights of his pre-authority golden years in 2002-03, and in fact, since succeeding Nasser Hussain he averages an unworthy 37.95 over 46 Tests. But everyone in the game knows that he can turn it on when he has to. Take his century at Old Trafford in 2005, for instance, which owed its origins to his matchless tour of Australia two winters earlier.

This week Vaughan has a chance to bring an end to his long-drawn-out rehabilitation period and get on with the business of leading England into the new era that he promised when he resumed the captaincy 18 months ago. Nobody doubts he belongs anymore, which means he in turn can dispel some of the doubts that have crept into the minds of his followers.

Kevin Pietersen, for instance, has cultivated a timorous streak since Vaughan was last assured of his position. Once upon a time he would invite opponents to come and have a go if they were hard enough; now he meekly acknowledges the skill of opposition bowlers or the treacherousness of the track, or the likelihood that a medium-sized run-chase will provide a serious challenge. His claim during the Hamilton Test, for instance, that his 131-ball 42 was one of the finest innings of his career was a testament to his new-found insecurity.

Ian Bell is another case in point - a pioneering strokeplayer when the mood catches him, but a man all too willing to back down when the going is not in his favour. Each of his seven Test centuries has been exquisite to behold, but on each and every occasion, one of his team-mates has reached three figures before him. Vaughan, by contrast, knows what it's like to fight singlehandedly for his country. His experience cannot be underestimated as England nudge and nurdle towards a new era.

This week's second Test is, therefore, a potential watershed for England. The squad that was so violently shaken up midway through the New Zealand tour is settling into a rhythm, but more importantly, the captain is growing back into his role. If he's been peevish of late, it can only be a good sign for England - he's no longer grateful just to be back and involved in international cricket, he's determined to start building on his foundations once again, and resume a pursuit of excellence that was aborted against his will, way back in 2005.