Introduction ON MARCH 18, 2003, the atmosphere in the ornate wood-paneled chamber of Britain's House of Commons crackled with electricity. The green leather benches of the nation's legislative chamber were packed to overflowing. Tony Blair was preparing to take his country to war alongside George W. Bush. Confounded, exhausted, and dismayed by the diplomatic failures at the United Nations during the previous few weeks, the British prime minister had set his course. The mood of Britain, though, was against risking the lives of its soldiers to topple Iraq's Saddam Hussein. In his own left-of-center Labour Party, intense hostility to a Republican president in the White House was combined with genuine doubts about the justification for war. Even as British troops gathered on the Kuwait-Iraq border, Blair faced a mounting rebellion among his supporters.

One senior member of his government, the former foreign secretary Robin Cook, had already resigned. Other ministers were preparing to quit. Scores of Labour members of Parliament (MPs) had resolved to vote against their own government. Beyond the political village of Westminster once-warm relationships with key allies in Europe lay badly broken.Tony Blair was unmoved. Ending Saddam's defiance of the international community was, in the phrase he had used over and again, ?the right thing to do.' That was his decision, he told colleagues in the British cabinet, whatever the cost. Government officials made contingency plans should he be forced to resign after the votes had been counted.

On that overcast March morning the prime minister was sure of a majority in Parliament because the opposition Conservative Party backed a war to topple the Baghdad regime. The risk he faced, however, was that more than half of his own supporters would rebel. In such circumstances, his premiership would be unsustainable. Britain and the rest of the world were being introduced to a leader they had not properly met. Blair had already transformed his party's electoral fortunes and had many times proved himself an accomplished politician. This, though, was the politics of conviction. He had everything to lose. Six years earlier, a few days before his forty-fourth birthday, Anthony Charles Lynton Blair had become the youngest British prime minister since the Napoleonic Wars of the early nineteenth century.

Three years later, he was the first prime minister in more than 150 years to father a child while in 10 Downing Street. In June 2001 he had won a second landslide election victory against the Conservatives, seemingly assuring himself a place in the record books as the longest-serving Labour prime minister in history. More than that, he had remade the landscape of British politics, wrenching the party he had rechristened New Labour from the barren socialist left into the fertile center ground. While his policies and campaign techniques had been borrowed from Bill Clinton's New Democrats, Blair had always been a politician impatiently dismissive of the old ideological divides between right and left. They owed their place, he thought, to an age that had passed with the fall of the Berlin Wall. He embraced the values of progressive politics while discarding the accumulation of sacred socialist texts that had locked his party out of government for nearly two decades. Most politicians start from a set of traditional political positions; Blair started from the values he had imbibed with his Christian faith. His political heroes were the leaders of the centrist Liberal Party, which had ruled Britain during much of the nineteenth century, rather than the giants of the Labour movement that he now led.

The product of a privileged private education and the son of a Conservative lawyer, he had always been at something of a distance from his own party. To the discomfort of many of his colleagues he saw himself as a national, rather than a partisan, leader, even though he had succeeded.