The British are to hold an inquiry into the origins and conduct of the Iraq war, and how Britain came to be so closely involved with the Americans in the 2003 Iraq invasion.

This touches on one of the most divisive and controversial issues in modern British politics and already the air is filled with acrimonious argument about the way the inquiry should be organized, who should conduct it and what it should cover.

The government's initial proposal was that the inquiry should be held in secret, and report after about a year, and that no blame should be apportioned to anyone for what went wrong. Five members have been named as members of the committee holding the inquiry, including a former senior civil servant, a well-known academic, an ex-ambassador and an eminent historian.

But no military figure has been included (despite strong feelings that British troops were poorly equipped); no legal expert has been nominated despite strong doubts about the legality of the invasion; and no senior politicians are present who might know about the way Cabinet policymaking really works.

This suggested formula has been greeted with public uproar. Under pressure the secrecy element has now been slightly modified to allow some evidence to be called in public. But it is clear that the approach commands no confidence. The British public want a full and open expose of the reasons it all happened, what went wrong, what, if anything, was achieved, and who was responsible for the many errors of judgment.

In particular the families of those whose sons and daughters were either tragically killed or maimed in Iraq want to know why they had to make this sacrifice. This writer was lucky. His son returned from military service in Basra safe and sound. Others were not so lucky.

The reason why so much intense bitterness surrounds the whole issue is that people feel the nation was misled from the start. Weak intelligence about Iraq's military capacity, and its terrorist connections, was mishandled by a plainly inexperienced prime minister, Tony Blair, who described intelligence reports as authoritative and detailed, which clearly they were not. Credence was given to the palpably absurd claim that Iraq President Saddam Hussein not only had weapons of mass destruction but nuclear missiles that could reach the West in 45 minutes.

Worse still, a highly dubious dossier was published by the government to try to prove this claim — a move so misleading that one senior official committed suicide as he saw the truth being distorted.

Persuaded by misinformation, and by the general feeling that America must be supported, both the Labour government and the Conservative opposition in Parliament, also led at the time by inexperience, went along with the invasion decision, although deep divisions emerged subsequently as the occupation descended into bloody chaos and error.

At the same time, people now want to know just what was agreed with the Bush administration and at what stage. Was the United Nations just bypassed by a U.S. leadership determined to destroy Hussein, with Britain on its coattails?

All this needs to be brought out by a proper inquiry. But there is also a sense that something even deeper has all along gone badly wrong.

Admittedly with hindsight, and in historical perspective, it can now be seen that Iraq invasion, together with the other equally tangled Afghanistan engagement, mark a turning point in modern history — perhaps in a way the Suez invasion did over half a century ago.

Suez was the occasion when the British at last realized they could no longer impose their will across a vast empire. The Iraq and Afghanistan wars show that the West, and America in particular, can no longer easily impose their will in the Middle East or anywhere else, or topple regimes and lecture the rest of the world on how to behave. Even the military contribution to the postinvasion Iraq occupation forces of numerous other nations, including Japan, has not disguised this fact.

U.S. President Barack Obama seems to have begun to understand this; President George W. Bush, and those around him, never did.

Meanwhile, with the last British troops having left Iraq, except for a small training contingent, and the Americans scheduled to leave finally at the end of 2011, the bombing and assassinations continue. A strong man will need to take control, despite all the dreams of establishing a settled and unified pro-Western democracy.

The outcome, and the whole pattern of the new Middle East, will be shaped not in Washington or any Western capital, but by a new alliance of global powers whose center may not be in the West at all.

This may be regretted and even denied by those who yearn to keep the old order of Western hegemony. But the onward march of history, technology and power cannot be resisted. A good inquiry should bring these new realities to light and help shape a wiser and more balanced world. A bad one will keep them secret and lead to more follies in the future .

David Howell is a former British Cabinet minister and former chairman of the Commons Foreign Affairs Committee. He is now a member of the House of Lords ([email protected] www.lordhowell.com).