Blair is right to make common cause with this brave and visionary President

Millions of Britons who wish their country had the right to entertain Mr Bush in a dignified and friendly manner will go unheard

It is possible to make a case against the Iraq war. It is even possible to be an intelligent person and still hope that President Bush is not re-elected. Moreover, few of those who supported the war and fervently wish for a Bush second term would claim that his first one has been perfect in every detail. We know about the law's delay, but it is taking too long to sort out Guantanamo Bay. Though it may well be that those men's detention has prevented thousands of deaths, their legal status ought to be resolved. There is also the embarrassing matter of steel tariffs.

So it is possible to make intelligent criticisms of the Bush presidency. But that does not apply to the Stop the War campaign, or to most of its supporters. There, we are dealing with unreason, towards the President and his country. To find an equivalent intensity of abuse, one would have to go back a generation and look up what some of the Rev Ian Paisley's less sophisticated supporters were saying about the Pope. To the Stop the War people, it is an article of faith that Mr Bush is a dunce surrounded by neo-fascist psychopaths and that many of his fellow Americans are mere land-based pirates bent on plundering the rest of mankind.

When someone insists that he is Louis XIV, he is given medicine, not an argument. There is almost as little point in arguing with the Bush-haters. But evidence might help to treat some of those who are not too far gone. Chuck Shumer, a Democratic senator from New York who cannot be accused of easy relations with the President, said the following: "Is he the smartest man ever to occupy the White House? No. Is he smart enough to be President? Of course.''

Those who have seen Mr Bush at work are at least as respectful. One hears accounts of brisk chairmanship; of a man who likes the clash of debate in order that he can clarify the issues and take the decisions. This is a President who surrounds himself with strong, able advisers, but remains in command.

It is also worth remembering his academic record. Unlike the young Al Gore, the young George Bush was not a diligent student. The future President did not believe in wearing out his brains by premature exertion. He was more interested in cold beer, hot girls and sports results. But he got better grades at Yale than Mr Gore did at Harvard. Mr Bush went on to Harvard Business School; you do not earn a Harvard MBA in a dunce's cap.

As for his administration, the new President did not expect foreign affairs to be a priority. He was inheriting an economy sliding into recession after a long boom and he knew what had happened to his father. In the Bush White House they did not need to put up posters with "It's the economy, stupid''. They were already aware of the phrase.

Then came 11 September and a reassessment. The administration, though with some backsliding from the State Department, became converted to the neo-Conservative diagnosis. According to this, it was not enough to deal with individual terrorists and terrorist incidents. There had to be an onslaught on the root causes: moral and political squalor in the Middle East. Much of the region was like a crumbling fever hospital, without medicine, doctors, or any means of quarantining its inmates. So it would be a constant source of dangerous infections, unless and until the US went in and treated the patients with the two super-drugs; democracy and human rights.

This strategy is questionable, but not on grounds of oppression, imperialism or indifference to suffering. The dangers arise from idealism and from an excessively generous assessment of human nature. It is assumed that material improvements will bring moral progress, and thus diminish the threat from terrorism. To some extent, this must be true. Terrorist groups have usually recruited their foot-soldiers from the wretched of the earth. But that does not necessarily apply to their officer class. The hijackers of 11 September were not impoverished. The risks of a clash of civilisations between the West and Islam, as described by Sam Huntington, cannot all be averted by higher living standards.

Yet those who are sceptical about the Bush policy also have a problem. The West cannot insulate itself from the Islamic world. In practical terms, what else can it do except encourage - and in extreme cases coerce - Islamic states so that they will stop maltreating their peoples?

Apropos of maltreatment, there is, of course, Palestine. The Palestinians must have a state. But President Bush has made that point far more often than any of his predecessors did. This, indeed, is yet another reason for cheering on his re-election. A second-term George Bush is the best American hope for the Middle East peace process.

In 10 years, if George Bush has his way, the peoples of the Middle East will have more votes, more human rights, more prosperity and more freedom. If the Stop the War campaign had its way, Saddam's torture chambers would still be in business. Anyone who cares about the welfare of the region should have only one anxiety about the President. While it is desirable that the Iraqis should take control of their own affairs as rapidly as possible, a continuing, large Western military presence may be necessary to secure the transition. The Allies went to Iraq, not as conquerors, but as liberators. The battle to complete that mission is still worth casualties.

Rights can be hard to reconcile. In Britain this week, tens of thousands of demonstrators will exercise their right to protest. Millions of others, who wish that their country had the right to entertain Mr Bush in a dignified and friendly manner, will go unheard. It is to be hoped that the President is also made aware of the silent voices.

The late General Vernon Walters, who served in several US administrations, used to say that he quite understood why so many Europeans hated the United States. "In 1919, we Americans cleared straight out of Europe, and you had a wonderful couple of decades, a marvellous period in your history. After 1945, we stayed around and it's all been so miserable for you. I can see why you are so nostalgic for the Twenties and Thirties.''

When General Walters was in full cry with that party piece, he could make hardened Frenchmen wince. It is sad to realise that these days, far too many British people are also guilty of gross ingratitude towards our greatest ally.

That is one reason for saluting Tony Blair this week. Even those of us who can see neither coherence nor integrity in his domestic programme must recognise that in his dealings with the Middle East and the United States, he has upheld this country's reputation, and its honour. He too is entitled to enjoy the ceremonial of a state visit. It is only unfortunate that the ceremonies will be disrupted by hysteria and hate-filled ignorance.