He may have two landslide elections under his belt, but Tony Blair has gambled his place in history on a successful war against Iraq. Political Correspondent Tariq Tahir looks at what the future holds for the MP from Sedgefield.

TONY Blair's political future stands at a crossroads, and whatever happens to him, the Prime Minister cannot be accused of not lacking the courage of his convictions. Anything other than a swift victory for the US and Britain will mean the end - or at least the beginning of the end - for the man that the people of Sedgefield first elected as their MP in 1983.

He has gambled his future by chucking in his lot with a man at best ridiculed as a simpleton by the rest of the world and at worst as the personification of everything bad about US foreign policy.

Last year, Mr Blair's backbench MPs, disbelieving that their leader could really stand so shoulder-to-shoulder with the Republican president, put forward the line he was only doing so in order to act as a restraint on George W Bush.

Their argument ran that as America's closest ally, Britain could act as a brake on the Washington hawks' relentless drive to war. Yet as that line has evaporated, a certain curious respect seems to have emerged among those backbenchers hostile to Mr Blair's stance.

It is clear that the Prime Minister actually believes what he is doing is right. Either that or he's so far in with the Americans that he can't get out and is putting on a damn good performance.Cynics jaded by the workings of the New Labour spin machine and Mr Blair's role at the heart of it might find the latter explanation the more plausible. Remember how a young Blair said he used to watch Jackie Milburn playing at St James' Park - except the Geordie hero was not playing at the time.

While it is certainly true New Labour has become the slave of focus groups and has been known to play fast and easy with the facts, its leader is a man driven by conviction.

Look beyond the caricature of Mr Blair and you will find a man who is motivated by a desire to do what he thinks is right. Most politicians have a similar desire; few are dismissed in the way that the Prime Minister has been.

Though he shows a pragmatic side - he believes that ''what works is what's right'' - he did not take on his own party over Clause Four because he fancied an easy life.

It is, however, in foreign affairs that the evangelical side of his nature manifests itself most clearly. At his last monthly televised press conference, he said people had doubted him over Kosovo and Afghanistan but, lo and behold, firm action has, he argued, prevented catastrophe and saved the world. "O ye of little faith, how could you doubt me then or now?" was his message.

But this time, the stakes are much higher.

Mr Blair's case for making war against Iraq has always been a moral one and it could not be anything else. The link between al Qaida and Saddam has been shown to be spurious, Saddam's weapons programme has been slowed by inspections and so-called intelligence dossiers have been lifted from the Internet. Then there have been so many squabbles within the United Nations that it has become increasingly difficult to justify the war as the UN's will.

So Mr Blair's argument has boiled down to the historical comparison between the Iraqi dictator's regime and the appeasement of Adolf Hitler in the 1930s. Millions of lives would have been saved had the international community stopped Hitler before he embarked on the Holocaust - and so thousands more lives can be saved if Saddam is stopped before he puts his weapons of mass destruction to full use.

There can be only two different outcomes to the war. The first has Tony Blair cast in Churchillian terms as a victorious war leader, the people of Baghdad falling gratefully at his feet after he's freed them from tyranny in a five-day war in which casualties were light. Mr Blair would then ride roughshod over Gordon Brown and even take Britain into the euro.

The other scenario sees a slow, messy, bloody war and has the Prime Minister having to explain away day after day the mounting casualties among British troops and Iraqi civilians. Anger over his disregard for the United Nations galvanises his party and a weakened Prime Minister clings on, beating off challenges over foundation hospitals and student tuition fees until finally quitting. His place in history should have been assured by his two historic landslide election victories but instead he is remembered for the messy way in which his term fizzled out - rather like John Major is remembered not for winning an unwinnable election in 1992 but for the way his premiership dribbled away amid internal squabblings.

The Blair Project and New Labour always had to come to an end at some time, but in 1997 no one could possibly have predicted that its fate would have been entwined with that of an unpopular right-wing Middle Eastern dictator and an unpopular right-wing US president.