Two and a half weeks ago, the shadows that had hung over Tony Blair's prime ministership since the end of major combat operations in Iraq suddenly fell especially dark. Kenneth Bigley, a British engineer kidnapped in Iraq, was under sentence of death. The two Americans captured with him had already been beheaded. Confirmation of each American death had come via a grisly Internet video, and Bigley's death was expected to follow. As in many newsrooms across Britain, we crowded around the television that Wednesday evening, waiting, partly in dread, partly in macabre fascination, for the news that would surely come.

Yet the fatal notice did not come. Instead, before finally slaughtering Bigley last week, the kidnappers posted two harrowing videos of the British hostage begging for his life. In both, his message was addressed directly to the prime minister: "I need you to help me now, Mr. Blair," he said, "because you are the only person on God's earth who can help me."

On this side of the Atlantic, the videos served to focus attention not only on the barbaric methods of the hostage-takers but also on the chaos in Iraq and on Blair himself as the American president's puppet and the author of British misfortune. The prime minister's alliance with George W. Bush, who is widely seen here as having dragged Britain into a disaster, has become a huge political liability, one that Downing Street tries, often effectively, to play down.

What's more, Britons who followed the first debate between President Bush and Sen. John F. Kerry felt their contributions to the U.S. war effort passed almost unmentioned, even by the president's supposedly worldly, alliance-loving Democratic challenger. Being America's ally today is seen here as a dangerous, thankless task.

For Blair, the timing of the hostage videos could hardly have been worse. The tape appeared just days before he and his cabinet were due in Brighton for the annual Labor Party conference, where some activists were plotting an all-out revolt against British involvement in Iraq. They wanted a debate on the war and a date for British troops to be withdrawn. The last thing Blair needed was a dead British hostage to haunt proceedings. The next to last thing he needed was a live hostage, with fiercely antiwar and publicity-conscious relatives appealing to the prime minister to save his life. Then, to heighten Blair's dilemma, the specter of Bigley appeared again on our screens, this time shackled and caged and branding the prime minister a liar.

If Abu Musab Zarqawi, the reputed leader of the presumed hostage-takers, was hoping to use Bigley as an opportunity to separate the United States and its most loyal ally in the way that the Madrid train bombings had divorced Spain from U.S. policies in Iraq, this was almost certainly a miscalculation. The videos of a sobbing Bigley ultimately did more to foment disgust with the kidnappers. His death will doubtless do the same. What the hostage crisis confirmed for the British public, however, was just who was in charge when it came to decisions such as how to handle a Briton's fate in Iraq. And it wasn't Prime Minister Blair.

The beheadings of the Americans launched much more than a death watch for Bigley. It began an extraordinary period of diplomatic signals and counter-signals about the possible release of Iraq's two leading female weapons scientists in return for the British hostage. Two Iraqi officials had said that their release was imminent. In London, British officials insisted that if the Iraqi women were to be released, that decision would be made quite separately from hostage considerations.

Then came word from the U.S. Embassy in Baghdad, blunt and to the point: No one was going to be released.

The Iraqis may have been handed sovereignty, but it was now clear where authority lay. Soon, the interim Iraqi prime minister, Iyad Allawi, who had recently arrived in New York from London, was saying the same: We cannot negotiate with kidnappers.

If Ken Bigley died, his relatives reflected acerbically, his death warrant would have been signed by the Americans.

We do not know why Bigley was initially treated differently from the two Americans. It is now clear that, for all their public insistence to the contrary, British officials had made contact with the extremists behind the scenes and may have indicated a willingness to negotiate.

That is one possible reason. Another theory is that the Bigley family's energetic maneuvers on TV and in videos, which were tailored -- probably on Foreign Office advice -- to his Muslim captors, had an effect. Certainly, his relatives seemed to establish a bizarre kind of dialogue that may have encouraged his kidnappers to consider Bigley more of an asset alive than dead. The U.S. authorities were never going to negotiate, so punishment rather than publicity was the swift outcome for the American captives. With the British, though, there seemed to be not only the prospect of a deal, but the possibility of continuing publicity. Why execute the man while he might still prove useful?

The most sophisticated theory, though, is that Zarqawi or his followers intended to use Bigley to erode the increasingly fragile links that exist between Britain and the United States. Here, the hostage-takers' methods appear to have backfired. A majority of the British public was, and remains, opposed to the Iraq war. But Britons in general have supported the refusal of successive governments to deal with hostage-takers. There is also a distinctly unsympathetic strand of British opinion, according to which Bigley had knowingly traded his safety for the huge pay available for working in Iraq and was at least partly responsible for his own misfortune. It is not a charitable view, but it tempered the initial public outcry.

Like most successful politicians, Blair is also a fortunate politician. His stroke of luck was that many in Britain had recently followed the high-profile and singularly unsuccessful efforts of French diplomats and politicians to secure the release of two kidnapped French journalists. Throughout the hostage dramas of the 1980s in Lebanon, British governments came in for frequent criticism that they were not doing enough and that their approach was defeatist. This time, though, British officials could cite the French example as proof that even the most energetic efforts had brought no result.

Opinion polls show that the British public is more resigned than indignant. Asked if there was anything Blair could or should do to obtain Bigley's release, the public was initially split, 50-50. The tally soon settled almost 70-30 in favor of the view that there was nothing the prime minister could do, and it stayed that way until news came of Bigley's death. In other words, Britons had few illusions about the prime minister's power to influence kidnappers -- or indeed any other aspect of the continuing hostilities in Iraq. Indeed, as news of the hostage's beheading broke, Bigley's Liverpool-based relatives said that they believed the government had done everything possible to secure his release "in this impossible situation."

This does not mean, however, that the Bigley case has been without fallout for Blair or that it will not continue to affect the prime minister, who plans to go for a third term in elections expected next year. Bigley's plight brought the Iraq war back into the headlines. It ensured that the Labor Party conference scheduled a debate on Iraq -- albeit one that was stage-managed in almost Stalinist style. Accusations that U.S. authorities had scuttled a deal to release the two female scientists gave the lie to the British government's boast that real sovereignty now rested with the interim Iraqi government. Worst of all, it made the prime minister look once again like a very junior partner of George Bush Inc.

Bigley's death reminds the British that, where Iraq is concerned, they have made their bed with the Americans -- something Blair has tried hard to make them forget. Until the kidnapping, the British government had tried to create the impression that Iraq had become an exclusively American problem. The government rejected all suggestions from the Bush administration that it might increase troop strength in Iraq or expand its operational area. All the reported violence was in the U.S. zone of occupation. U.S. troops were blamed for heavy-handed tactics. When the Conservative Party's defense spokesman noted, in a radio interview, that British troops around Basra were back in hard helmets and armored transports and were being subjected to attacks, this was news to many people.

Downing Street had also done a consummate job of minimizing Blair's public contact with Bush and senior administration officials. Bilateral visits were kept formal and, if possible, under wraps. Photographs a deux at international gatherings, such as the G8 summit, were avoided. Britain's foreign secretary, not Blair, represented Britain at the recent U.N. General Assembly meeting in New York. If you ask his office when Blair plans to collect the U.S. Congressional Medal of Honor he was awarded more than a year ago, you are told no date has been set.

The British government instead has recently made a show of Blair's personal affairs and public contacts with Europe and other countries. When the American survey group released its report last week that there were most likely no weapons of mass destruction in Iraq before the invasion, Blair was traveling between Sudan and Ethiopia. Blair's minor heart procedure immediately after the party conference, preceded by his statement that he planned a third term in office but not a fourth, preoccupied the chattering classes to the exclusion of all else.

Bigley's horrifying captivity and death are unlikely to represent the last Iraq storm Blair will have to weather. An outcry is already brewing about over the survey group's report on Iraq's weapons. When Parliament reconvenes this week, Blair will face renewed pressure to issue a formal apology for supporting what a growing constituency regards as the U.S. president's ideologically inspired war. There is now a real possibility that in trying to cement the special relationship by following the Americans to Iraq, Blair may have accelerated its dissolution.

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Mary Dejevsky, chief editorial writer of London's Independent, was the newspaper's Washington bureau chief from 1997 to 2001.

Grim reminder: The fate of hostage Kenneth Bigley put more pressure on Prime Minister Tony Blair, placing the Iraq war back at the center of British politics.