The British and US governments gave three reasons for going to war with Iraq. The first was to extend the war on terrorism. The second was to destroy its weapons of mass destruction before they could be deployed. The third was to remove a brutal regime, which had tortured and murdered its people.

If the purpose of the war was to defeat terrorism, it has failed. Before the invasion, there was no demonstrable link between al-Qaida and Iraq. Today, al-Qaida appears to have moved into that country, to exploit a new range of accessible western targets. If the purpose of the war was to destroy Saddam Hussein's weapons of mass destruction before he deployed them, then, as no such weapons appear to have existed, it was a war without moral or strategic justification.

So just one excuse remains, and it is a powerful one. Saddam Hussein was a brutal tyrant. While there was no legal argument for forcibly deposing him on the grounds of his abuse of human rights, there was a moral argument. It is one which our prime minister made repeatedly and forcefully. "The moral case against war has a moral answer: it is the moral case for removing [Hussein]," Tony Blair told the Labour party's spring conference in February. "Ridding the world of [Hussein] would be an act of humanity. It is leaving him there that is in truth inhumane."

Had millions of British people not accepted this argument, Tony Blair might not be prime minister today. There were many, especially in the Labour party, who disagreed with his decision but who did not doubt the sincerity of his belief in the primacy of human rights.

There is just one test of this sincerity, and that is the consistency with which his concern for human rights guides his foreign policy. If he cares so much about the welfare of foreigners that he is prepared to go to war on their behalf, we should expect to see this concern reflected in all his relations with the governments of other countries. We should expect him, for example, to do all he can to help the people of Uzbekistan.

There are over 6,000 political and religious prisoners in Uzbekistan. Every year, some of them are tortured to death. Sometimes the policemen or intelligence agents simply break their fingers, their ribs and then their skulls with hammers, or stab them with screwdrivers, or rip off bits of skin and flesh with pliers, or drive needles under their fingernails, or leave them standing for a fortnight, up to their knees in freezing water. Sometimes they are a little more inventive. The body of one prisoner was delivered to his relatives last year, with a curious red tidemark around the middle of his torso. He had been boiled to death.

His crime, like that of many of the country's prisoners, was practising his religion. Islam Karimov, the president of Uzbekistan, learned his politics in the Soviet Union. He was appointed under the old system, and its collapse in 1991 did not interrupt his rule. An Islamist terrorist network has been operating there, but Karimov makes no distinction between peaceful Muslims and terrorists: anyone who worships privately, who does not praise the president during his prayers or who joins an organisation which has not been approved by the state can be imprisoned. Political dissidents, human rights activists and homosexuals receive the same treatment. Some of them, like in the old Soviet Union, are sent to psychiatric hospitals.

But Uzbekistan is seen by the US government as a key western asset, as Saddam Hussein's Iraq once was. Since 1999, US special forces have been training Karimov's soldiers. In October 2001, he gave the United States permission to use Uzbekistan as an airbase for its war against the Taliban. The Taliban have now been overthrown, but the US has no intention of moving out. Uzbekistan is in the middle of central Asia's massive gas and oil fields. It is a nation for whose favours both Russia and China have been vying. Like Saddam Hussein's Iraq, it is a secular state fending off the forces of Islam.

So, far from seeking to isolate his regime, the US government has tripled its aid to Karimov. Last year, he received $500,000,000, of which $79,000,000 went to the police and intelligence services, who are responsible for most of the torture. While the US claims that its engagement with Karimov will encourage him to respect human rights, like Saddam Hussein he recognises that the protection of the world's most powerful government permits him to do whatever he wants. Indeed, the US state department now plays a major role in excusing his crimes. In May, for example, it announced that Uzbekistan had made "substantial and continuing progress" in improving its human rights record. The progress? "Average sentencing" for members of peaceful religious organisations is now just "7-12 years", while two years ago they were "usually sentenced to 12-19 years".

There is little question that the power and longevity of Karimov's government has been enhanced by his special relationship with the United States. There is also little question that supporting him is a dangerous game. All the principal enemies of the US today were fostered by the US or its allies in the past: the Taliban in Afghanistan, the Wahhabi zealots in Saudi Arabia, Saddam Hussein and his people in Iraq. Dictators do not have friends, only sources of power. They will shift their allegiances as their requirement for power demands. The US supported Islamist extremists in Afghanistan in order to undermine the Soviet Union, and created a monster. Now it is supporting a Soviet-era leader to undermine Islamist extremists, and building up another one.

So what of Tony Blair, the man who claims that human rights are so important that they justify going to war? Well, at the beginning of this year, he granted Uzbekistan an open licence to import whatever weapons from the United Kingdom Mr Karimov fancies. And his support goes even beyond that. The British ambassador to Uzbekistan, Craig Murray, has repeatedly criticised Karimov's crushing of democracy movements and his use of torture to silence his opponents. Like Roger Casement, the foreign office envoy who exposed the atrocities in the Congo a century ago, Murray has been sending home dossiers which could scarcely fail to move anyone who cares about human rights.

Blair has been "moved" all right: moved to do everything he could to silence our ambassador. Mr Murray has been threatened with the sack (firing), investigated for a series of plainly trumped-up charges and persecuted so relentlessly by his superiors that he had to spend some time, like many of Karimov's critics, in a psychiatric ward, though in this case for sound clinical reasons. This pressure, according to a senior government source, was partly "exercised on the orders of No 10".

In April, Blair told us that he had decided that "to leave Iraq in its brutalised state under Saddam was wrong". How much credibility does this statement now command, when the same man believes that to help Uzbekistan remain in its brutalised state is right?