Assuming you read at average speed, by the time you get to the bottom of this column, the war in Iraq will have cost the United States another $760,000. More than $4 million of US taxpayers' money ebbed away in the 18 minutes it took George W. Bush to explain to his country and the world last week why the war he ordered would last well beyond his presidency.

During an eight-hour working day, US tax dollars spent in the battle zones of Iraq total $112 million. These figures are extrapolated from a report by the Congressional Research Service (CSR), a bipartisan agency which provides research and analysis for the US Congress. It put the war's average cost in 2007 at around $10 billion a month.

That translates into $333 million a day, $14 million an hour, $231,000 a minute and $3,850 a second. Even for the world's richest country, this is serious money.

It dwarfs what the United States is spending on efforts to alleviate the huge humanitarian crisis that unfolded after the 2003 invasion. Sectarian fighting has driven more than 4 million people from their homes, a population displacement without parallel in modern Middle Eastern history.

The consequences of the war were never part of the planning. And its high cost is a long way from the Bush administration's optimistic initial estimates.

Then Deputy Defense Secretary Paul Wolfowitz, one of the war's chief promoters, even predicted the post-invasion phase would be self-financing.

"There is a lot of money to pay for this that doesn't have to be US taxpayer money ... We're dealing with a country that can really finance its own reconstruction, and relatively soon," he said on March 27, 2003.

Depends on your definition of "soon", of course. The Government Accountability Office reckons it will take years before Iraqi oil flows at full capacity.

The number of US troops in Iraq is now at a record high — 168,000. The cost of the war is not projected to decline despite plans for a phased withdrawal that will reduce troop levels by next summer to what they were before the so-called surge.

Troop levels are one of the factors that determine the cost of the war. Another cost driver: repairing and replacing worn-out equipment, from helicopter engines and tank tracks to Humvees, armored personnel carriers and machine guns.

Opponents of the war have begun to focus on its high cost and stress what could be done with the dollars spent in Iraq — improving American education and healthcare and fixing ageing US infrastructure.

The comparisons almost invariably centre on things that could be done or bought in the United States for the benefit of Americans. Iraqis do not figure prominently in these analyses and the humanitarian disaster now unfolding is not much of a topic of discussion among Washington policy-makers.

That, at times, dismays international aid officials who deal with the terrified multitudes who have fled waves of ethnic cleansing in the aftermath of the US invasion. Around 2 million went to neighbouring countries, mostly to Jordan, Syria and Egypt, by the count of international relief organisations.

Another 2.2 million fled from their homes and sought refuge elsewhere in Iraq. Shiites driven out of Sunni neighbourhoods, Sunnis fleeing Shia districts, Arabs expelled from Kurdish areas, Kurds from predominantly Arab districts.

The movement dwarfs even the great population dislocations prompted by the 1948 creation of Israel, when an estimated 750,000 Palestinians fled their homes in fear for their lives.

Many of the internally displaced Iraqis — IDPs in the language of aid organisations — live in grim conditions, in makeshift camps without running water, electricity, even latrines.

Improving such conditions would be cheap, measured against the cost of the war, but appeals for increased funds have fallen on deaf ears.

This summer, the Iraq Chief of Mission of the International Organization of Migration (IOM), Rafiq Tschannen, said "only a fraction" of internally displaced Iraqis were getting basic assistance. It was difficult to understand, he said, why there was so little response to appeals for help.

Not all that difficult, really. Part of the international community suffers from what relief workers call "compassion fatigue." And for the United States, making the humanitarian crisis a public priority would be tantamount to admitting failure in Iraq.

After all, the US invasion was meant to have brought democracy, security and stability, not civil war and mass flight.

Without much fanfare, US contributions to various relief organisations quadrupled in 2007, to just under $200 million from $43 million in 2006, pocket change in terms of the war's cost. The sharp increase makes Washington the biggest single donor in the refugee crisis, according to the US Department of State.

As to the $85 million appeal by the IOM, made in June — by September, the organisation had received $6 million, 5 million from the United States and 1 million from Australia.

The shortfall, $79 million, would be covered by less than six hours of war spending.

Bernd Debusmann is a Reuters columnist. The opinions expressed are his own