Take a close look at Mr Blair. Does he seem like a man on his last legs?

What a topsy-turvy world it is. Nothing is quite what it seems. By common consent an ageing, exhausted and beleaguered Tony Blair is in the middle of a political crisis which could finish him off as a leader. Only if he can leap over the impossibly high hurdles placed in front of him this month will he be free to flourish on undemanding terrain and stride towards the glories of a third election victory. In contrast, Michael Howard is on a high, looking 10 years younger than in the days when he had something of the night about him. What is more, Blair's wide-open goals in the form of the vote on top-up fees and the publication of the Hutton report are still to come.

These common assumptions do not ring true to me. We are being deceived - or perhaps we are deceiving ourselves. Like detectives in a film noir we read the wrong signs even when the right ones are staring us in the face.

The talk of Blair's appearance and frame of mind is symptomatic in its misguidedness. As anyone who watched him on Breakfast with Frost last week could see, he is fit and tanned, looking good for 50. I have a broader theory on the physical appearances of political leaders. They do not change quite as dramatically as we assume. It is our perceptions that alter.

In the mid-1990s, for example, William Hague was young, dynamic and telegenic. Soon after he became leader of the Conservative Party he became that odd-looking chap who looked even odder in a baseball cap. In reality he looked OK in that cap - rather trim and chiselled. I suspect most would agree with me now, but that is because we view Hague differently again. Now we regard him as a TV celebrity, the former and future leader of a political party. It was the same with Neil Kinnock. In the late 1970s and early 1980s he was the young, charismatic TV star. When he was Labour's leader he became a bald windbag. When Blair is looking good, as he is at the moment, we are amazed at how old he seems. We deceive ourselves.

Not only is the Prime Minister looking good, he is also in an optimistic frame of mind. Those who work with him and have seen him at close quarters testify to his good-humoured chirpiness. He is on something of a high. This is odd. He is relaxed in a genuine full-blown crisis, and feels uneasy when everything is going well. In the early years of his leadership, when Labour was 30 points ahead in the polls, he tended to warn gloomily that the battle was really much closer. A statement from Hague on rural post offices could throw Downing Street into a minor panic. Yet I recall interviewing Blair at the height of the fuel dispute in the early autumn of 2000 when the country was grinding to a halt. He was as calm and good-humoured as he is at the moment.

I suspect that, as with so much else, Blair's political apprenticeship in the 1980s offers a partial explanation for this. He was brought up politically in a dark gloom, in which Labour lost elections. Being in a crisis now must be like returning to that political womb. He is also out campaigning, putting the case for top-up fees for universities. He tends to enjoy such campaigns, especially when they are limited to those issues which allow him to take on a large section of his own party - with, of course, the support of Rupert Murdoch's newspapers and some Conservative MPs. These have been the dynamics of his most energetic acts of persuasion - from his successful abolition of Clause 4, to the justification of the war against Iraq, and the introduction of foundation hospitals. Blair does not evangelise in the same way on issues relating to Europe or on the introduction of congestion charges. That is because, for all the support he would receive from his own party, he would, nevertheless, have a tougher time persuading a sceptical electorate, and the media itself.

Even so, the selective nature of his high-profile campaigns is not a reason to oppose them. It is certainly not a justification for opposition to top-up fees. Blair's arguments in favour of this policy are far more detailed and precise, compared to the series of precarious hypotheses on which he based his public case for the war against Iraq. His lengthy speech on the policy delivered last Wednesday was full of meaty and persuasive arguments. Labour MPs would be daft to inflict a near-fatal blow over such a policy. At the very least, he is addressing the issue of how to fund yet another cash-starved public service. He is also increasing, substantially, the level of public spending on universities. The policy is not an alternative to more generous public spending, but a significant and necessary addition.

Meanwhile, in a mood of heady euphoria, the Conservatives are striding blindly into a new crisis over "tax and spend", the issue that played a large part in their defeat at the last election. Their Education spokesman, Tim Yeo, admits that universities are suffering from a lack of resources. As far as I can tell, he accepts that universities will need more money, even if the Conservatives scrap Labour's ambition to increase student numbers. So where will the money come from?

Nicholas Soames, the Conservatives' shadow Defence Secretary, has already indicated that he will be calling for a higher spending pledge in his policy area. Other shadow Cabinet ministers have also implied a need for more resources in other public service areas. It is not easy to see how these sums equate with the Conservatives' desire to cut taxes. In going for an easy hit over top-up fees, Howard is landing himself in some considerable, long-term difficulties.

Similarly, he has played for some prematurely sensational headlines over the Hutton inquiry. By persistently trailing the possibility that Blair lied over the naming of Dr David Kelly, the Conservative leader is in danger of raising the Hutton hysteria in advance, making the actual publication much more of an anti-climax. It is Howard himself who should be worried by his positioning in this defining month. Blair, still ahead in most mid-term polls and presiding over a still strong economy, has good cause for his optimism.

Nothing is what it seems. This extends to the other common assumption listed at the start of this column: that if Blair leaps over his two supposedly mammoth hurdles this month he has a clear path to the next election. As he knows, the justified furore over the undiscovered weapons of mass destruction will not disappear. He also faces the challenge of finding more cash to sustain the recent significant improvements in public services. The vote on top-up fees is the beginning of a thunderous and divisive debate about public services, not the end. No wonder he is calm now. For Tony Blair, the hurdles of the next few weeks are the easy bit.