POLITICIANS, like people in general, should normally be judged by their actions not words. But after a chain of events has been set irrevocably in motion, when it is too late for actions to change history’s course, there are times when words can speak louder than deeds. Tony Blair’s address to the Labour Party conference was such a moment.

As I listened to Mr Blair in Brighton on Tuesday, I suddenly — and totally unexpectedly — felt a twinge of the same physical panic which engulfed us all on that horrible Tuesday three years ago. As the Prime Minister’s speech veered from a perfectly lucid account of domestic policies in Britain into a tangled and incoherent apologia for the disaster in Iraq, it suddenly struck me that Britain was led by a man who had lost his reason. This sounds exaggerated, so let me be precise.

To judge by the three pages on Iraq in his speech to the party conference, Mr Blair has “lost his reason” in two very literal ways: He has lost his ability to make reasoned judgments about the War on Terror. And he has therefore lost the primary raison d’être of any prime minister, which is to protect Britain and British interests in a dangerous and complex world.

I recognise that this is a terrible accusation to level against any politician – and that none of the other commentators in Brighton seemed to react in the same way as I did. I will therefore quote at length from Mr Blair’s speech, so that readers can judge for themselves whether I am the one whose reason has disappeared.

But first, let me explain why I attach such significance to a single speech. What Mr Blair said about Iraq in Brighton was not just some thoughtless off-the-cuff comment. This was the most self-conscious passage in the most heartfelt speech he has delivered — the outcome of weeks, maybe months, of introspection, analysis and mental struggle. By all accounts, it was written by the Prime Minister himself, not by a spin doctor or PR hack. This was, in short, the distillation of all Mr Blair ’s wisdom on the most important question of his political life. So if I am right in judging this passage confused to the point of unreason, serious questions must be raised about his capacity to stay in his job.

Here is Mr Blair’s main justification for invading Iraq, offered with more than a hint of intellectual pride:

“There are two views of what is happening in the world today. One view is that there are isolated extremists engaged in essentially isolated acts of terrorism. That what is happening is not qualitatively different from the terrorism we have always lived with. If you believe this, we carry on the same path as before September 11. We try not to provoke them and hope in time they will wither.

“The other view is that this is a wholly new phenomenon, worldwide terrorism based on a perversion of the true, peaceful and honourable faith of Islam; that its roots are in the madrassas of Pakistan, the extreme forms of the Wahhabi doctrine in Saudi Arabia, in the former training camps of al-Qaeda in Afghanistan. If you take this view, the only path to take is to confront this terrorism, remove it root and branch and at all costs stop it acquiring the weapons to kill on a massive scale.”

What is wrong with this analysis? Only that the logical implications of Mr Blair’s dichotomy are exactly the opposite from the ones that he draws. If the “new” terrorists are isolated gangs of madmen with no defined objectives, then the fear of “provoking” them is irrelevant, since nihilists cannot, by definition, be provoked. Such nihilists, far from being “traditional” terrorists, as the Prime Minister suggested, are the opposite of traditional groups such as the IRA, Basque militants, Hezbollah or Hamas, all of which have clearly defined objectives. The right course to follow against the first type of terrorists is what Mr Blair recommends for the second type: destroying them with overwhelming force. This, indeed, was the argument presented for the invasion of Afghanistan.

If, on the other hand, the “new” terrorism is really a malignant offshoot of the Wahhabi religious movement — then it is similar to traditional Irish and Palestinian terrorism, albeit more vicious and destructive. In that case, needless provocation should be avoided and the response must be political as well as by force. Moreover, if fundamentalism is at the root of the problem, why attack Iraq, a secular country where Wahhabis were almost unknown? Far from justifying the Iraq invasion, Mr Blair’s logic points towards regime change in Saudi Arabia or armed action to seize nuclear weapons in Pakistan.

The confusion gets even worse. Mr Blair points out that some of the terrorists now in Iraq are the same religious fanatics who oppressed the women of Afghanistan. But how does this justify the overthrow of the largely secular Saddam regime, which has sucked these maniacs into Iraq, while leaving much of Afghanistan to be reoccupied by the Taleban? Mr Blair’s answer would be funny if it were not so scary.

“But Iraq was not a safe country before March 2003,” he states. Then, to prove this contention and somehow link it with the invasion he makes his final leap of illogic: “Few had heard of the Taleban before September 11. Afghanistan was not a nation at peace . . . but the terrorists trained in the Hindu Kush could end up in British streets threatening our way of life.”

In sum, Mr Blair, seems to have convinced himself that Iraq and Afghanistan are effectively one country and that al-Qaeda, the Taleban and Saddam Hussein are all the same. Britain’s chattering classes haughtily patronise the 60 per cent of American voters who apparently believe that Saddam was behind 9/11. Yet in Britain we now have a Prime Minister whose whole Middle Eastern strategy rests on this same fiction, and whose analysis of global terrorism is so illogical that it makes President Bush sound like Socrates.

Mr Blair was once an intelligent and convincing leader. But Iraq has caused his brain to short-circuit, much as John Major’s did after the exchange-rate debacle. A prime minister who has lost his power to reason is too dangerous to keep in the job.

Times Recommends

• Resist urge to throw voters red meat
• Slay sacred cows and be candid
• We cannot let these 100 deaths deflect us