Three and a half years after "Operation Iraqi Freedom" began, the fallout from the United States' invasion of Iraq has hit home hard. U.S. voters on Tuesday delivered the Republican Party a devastating setback: the loss of its majority in both houses of Congress. In turn, they have been handed the head of Defence Secretary Donald Rumsfeld, the architect of both the decisive victory over Saddam Hussein and a savagely bungled occupation. Mr. Rumsfeld's departure, if long overdue, is welcome. In and of itself, however, it changes nothing. What needs to change is U.S. strategy in Iraq.

The country is in crisis. There is no precise formula to determine when anarchy and insurrection become civil war. There is no science to it, only inexact calculations based on rising body counts. Estimates of civilian deaths in Iraq since the U.S. invasion in 2003 vary dramatically -- the Iraqi Health Ministry this week put the figure at between 100,000 and 150,000 -- but by any measure it is a terrible slaughter. Civilian deaths from sectarian violence currently exceed 3,000 a month, the United Nations estimates. The U.S. military's death toll reached 105 for October, the fourth highest monthly total since the invasion. Regardless of whether this is a "low-intensity civil war" (to use the construction of Britain's former ambassador to Baghdad) or merely a serious outbreak of sectarian violence, Iraq is a mess.

Months before setting out to "disarm Iraq, to free its people and to defend the world from grave danger," U.S. President George W. Bush predicted "an era of new hope" would follow any invasion. In October of 2002, he said that once Saddam Hussein's tyrannical regime was ousted, "Iraq's people will be able to share in the progress and prosperity of our time." He pledged to "help the Iraqi people rebuild their economy, and create the institutions of liberty in a unified Iraq at peace with its neighbours." Mr. Bush's father, the pragmatic president George H.W. Bush, had, during the 1990-91 Gulf War, resisted the temptation to push on to Baghdad and overthrow Mr. Hussein. He calculated that the political and human costs of an invasion were too high. But Bush the younger, a foreign-policy romantic, wanted to complete the job. He could not resist the siren call of finishing what his father started or the dreamy notion of democracy taking root in Mesopotamia.

Mr. Bush asked: "Are the peoples of the Middle East somehow beyond the reach of liberty? Are millions of men and women and children condemned by history or culture to live in despotism? . . . I, for one, do not believe it. I believe every person has the ability and the right to be free." These are noble sentiments, sentiments we supported before the invasion, arguing that a free Iraq could "provide a beacon for other Arab countries -- spurring political, economic and even religious reforms."

However, the day after the invasion of Iraq began, we also wrote that while the "U.S.-led forces are capable of winning a war on their own . . . winning the peace will be more complicated." We urged that the international community come together to rebuild the country, and we advocated a prominent role by the United Nations in that process.

Instead, after it toppled Mr. Hussein, the Pentagon was entrusted with rebuilding Iraq. Mr. Bush's high-minded objectives were consistently contradicted by his administration's crude, imperial policies. Mr. Bush and his acolytes have sabotaged a military victory by their inattention, their indifference and their arrogance. They disbanded Iraq's army and police forces, making it possible for a powervacuum to develop which set off fighting between Iraq's religious and tribal groups. They allowed Iraq's borders to remain unguarded, permitting militants to cross into the country in large numbers after Mr. Hussein's defeat. The result is that ahomicidal regime has been replaced with what may yet end as a generalized bloodbath.

The real test was always in winning the peace, and it is there that the U.S. has failed catastrophically. Forget the "institutions of liberty" that the U.S. administration hoped to sow in Iraq and the Middle East. Even the most rudimentary of American objectives -- the replacement of a destabilizing force with a non-menacing government that won't collapse and can maintain Iraq's territorial integrity -- may well be out of reach.

If not the creation of "a new era of hope," then, what of Mr. Bush's claim that the invasion of Iraq would make the world a safer place? After Colin Powell, then secretary of state, appeared at the UN Security Council on Feb. 5, 2003, to expose Iraq's efforts to conceal weapons of mass destruction, we wrote: "There can be little doubt that Iraqi President Saddam Hussein's regime is lying." We argued that the onus was on Mr. Hussein to fulfill his responsibilities to the international community and co-operate with inspectors.

As we now know, Iraq did not possess such weapons. Mr. Hussein was a threat, but in the end only to his own people. The UN inspections had worked. Along with many others -- even Mr. Powell now says he was taken in -- this newspaper was swayed by the U.S. evidence that Mr. Hussein possessed weapons of mass destruction. However reluctantly, we concluded that the war was justified, a position we now regret.

The removal of a murderous tyrant who had used torture and poison gas against civilians is not a bad thing. No one should forget the terrible crimes committed by Mr. Hussein and his henchmen; the genocidal Anfal campaign waged against Iraq's Kurds alone cost more than 100,000 lives. Saddam Hussein's war-making against Iran is estimated to have killed another one million people.

But the decapitation of Iraq's malevolent leadership has itself unleashed terrible forces. Iraq's elected government has proven hapless, powerless to stop the violence from the fierce Sunni and Shia resistance and helpless against what now seems an implacable juggernaut headed toward partition of the country. There to pick up the pieces in Shia-dominated southern Iraq is Iran, a country that really does pose a serious threat. Consider this: The effect of the U.S. adventure in Iraq may yet be a Greater Iran.

A final U.S. folly is founded on its claims of the existence of a "sinister nexus" between Mr. Hussein's Iraq and al-Qaeda. What was not remotely true then is incontestably true now. The country has become a breeding ground for extremism and safe haven for jihadis. Al-Qaeda in Iraq is claiming to have 12,000 fighters. By its invasion, did the U.S. really "defend the world from grave danger"? It did not.

That brings us to today and the question of what will follow Mr. Bush's self-described political "thumping" by voters.

The U.S. is forging ahead with a $592-million (U.S.) project to construct a massive embassy in Baghdad, but it is a hollow and unwelcome gesture, more an expression of pro-consulship than friendship. Indeed, there is a growing view that despite the current chaos, the presence of U.S. and British troops is, as the British General Sir Richard Dannatt suggested recently, "exacerbating" the deteriorating situation by inciting violence. It should be obvious by now that Iraq's future will not be decided within the walls of intimidating new edifices, or settled by U.S. and British soldiers. It will be decided by Iraqis. It is time for a halt to the proliferation of imperial symbology in Iraq.

It is time also that the U.S. presented a firm timetable to scale back its and its allies' military presence. Not a full and immediate evacuation, not "cut and run," but a sequence of staged withdrawals over a period of 18 months. We are mindful of the extreme danger of civil war in Iraq, but the responsibility to hold back the forces of violence cannot be vested in the U.S. army of occupation indefinitely. Iraqis need to own up to their responsibility for their future. There has been more than three years to train and equip Iraqi security forces (to replace those foolishly disbanded after Mr. Hussein's fall), and because of underinvestment even this basic responsibility has not been fulfilled. Iraq's army and police must with urgency be brought up to speed.

The U.S. must also do what it should have done the day Mr. Hussein's regime fell, and involve the United Nations in ensuring Iraq's security and deterring Iranian expansionism. The elimination of the traditional Iraq-Iran regional balance of power is a concern not only to the U.S. but to other countries, including other powers in the region. They must commit to share the burden.

Finally, the U.S. must swallow its pride and engage in dialogue even with those countries it finds reprehensible, including Syria and, yes, Iran. Robert Gates, Mr. Rumsfeld's successor, has previously advocated direct talks between the U.S. and Iran. Mr. Bush must overcome his intransigent opposition to the idea. He does not have to like the governments of Syria and Iran -- and there is little in either to admire -- but the U.S. must develop a strategy for containing the mischief such countries are capable of without sacrificing yet more of its overstretched military. Containing your enemies is usually smarter than fighting them.

As the U.S. knows all too well from its modern history, there is no sure way out of a quagmire, but what is certain is that whatever plan the U.S. administration had for Iraq is in ruins. The time for George-W.-Bush-style foreign policy romanticism is at an end.