IRAQ - Cheney & McCain Hold Steady.

Cheney, who arrived in Baghdad with his wife and daughter, and McCain both promised on March 17 that Washington's commitment to Iraq would not waver despite signs of a recent resurgence in violence in the country. Their comments, made on separate occasions, contrasted with a set-piece speech on Iraq by Mrs Clinton, the Democratic presidential hopeful, in which she highlighted her vow to start bringing American troops back home in a plant to be worked out within 60 days of taking office.

At an appearance with PM Nouri al-Maliki, Cheney emphasised "the unwavering commitment of the US to support in finishing the difficult work that lies ahead". He cited "phenomenal" improvements in the security and economic fields since his last visit 10 months ago - a time when the "surge" in US forces had not yet reached its height. He urged allied Sunni Arab states to resume their full diplomatic missions in Baghdad and thus hold in check the influence of Iran's Shi'ite theocracy in this country.

On the previous days there had been a spike in violence, with the killing of a number of US military personnel and the kidnap and murder of a prominent Christian bishop. On March 17 a woman suicide bomber killed at least 53 Shi'ite worshippers near the Imam Hussein Shrine in Kerbala' and bombs in Baghdad killed four people.

Cheney later said the US was still pressing Iraq to pass legislation on petroleum and provincial elections. The top US commander in Iraq, Army Lt Gen David Petraeus, added that, at the bidding of Maliki, US officials had asked Western oil and electricity companies to "re-engage" with Iraq.

The number of US troops in Iraq will return to pre-surge levels of about 130,000 this summer. Gen Petraeus in April will report to Congress and will recommend that the Pentagon delay further reductions until the military assesses the impact of removing the surge's five combat brigades.

After meeting with Abdul Aziz al-Hakim, leader of the Shi'ite Supreme Islamic Iraqi Council (SIIC), Cheney said the Iraqis had made a "tremendous amount of progress" on security and on the political front. But privately US officials are concerned that political progress has been limited, though. A bill intended to allow some former Ba'th Party members back into the government may end up causing as many problems as it fixes, for example.

Addressing 3,000 US troops at Balad Air Base 70 km north of Baghdad, Cheney on March 18 said: "You and I know what it means to be free. We wouldn't give such freedoms away and neither would the people of Iraq or Afghanistan, but in both of those countries, they're facing attack from violent extremists who want to end all democratic progress and pull them once again in the direction of tyranny. We're helping them fight back because it's the right thing to do and because it's important to our own long-term security". Cheney, an architect of the 2003 invasion, added: "As President Bush has said, the war on terror is an ideological struggle and as long as this part of the world remains a place where freedom does not flourish, it will remain a place of stagnation, resentment and violence ready for export... We have no intention of abandoning our friends or allowing this country...to become a staging ground for further attacks against Americans... Across this country, the more that Iraqis have gotten to know the Americans - the nature of our intentions and the character of our soldiers - the better they have felt about the United States of America".

Cheney and his family spent the night in a trailer at Balad, one of the largest US air bases in Iraq. In the early hours there was a barrage of mortar and artillery fire lasting for several hours. Megan Mitchell, a spokeswoman for Cheney, told reporters travelling with him US troops on the base had launched pre-emptive fire against areas where they believed "the enemy is located". Cheney said no one had told him what the noise was.

Sen McCain was in Baghdad as part of week-long international trip which later included stops in Jordan, Israel, France and the UK. He was travelling on congressional business as a member of the Senate Armed Services Committee. But the trip is widely viewed as an attempt to burnish his foreign policy credentials ahead of the presidential election. He has staked his presidential campaign on staunch support for the war in Iraq, in sharp contrast to Mrs Clinton and Barack Obama, his potential Democratic opponents, who have vowed to bring US troops home. Mrs Clinton on March 17 said she was the only presidential candidate who could be relied on to end the war, accusing Obama of sending mixed signals over Iraq.

Shocking War Costs: Six months before the start of the US led-invasion, then White House Economic Adviser Larry Lindsey estimated the war in Iraq could cost as much as $200 bn. The claim, which cost Lindsey his job, was dismissed as baloney by then Defence Secretary Donald Rumsfeld, whose own estimate was $50-60 bn. Andrew Natsios, head of the Agency for International Development, estimated the reconstruction of Iraq would cost the US $1.7 bn. These estimates have proved to be what the war's critics say is just one of many grievous miscalculations. Serious estimates suggest it will be, except for World War-II, the most costly in US history.

The US government is spending $12 bn a month in Iraq. The Joint Economic Committee (JEC) of Congress says the war has so far cost a US family of four $16,900, a bill which could rise to $37,000 by 2017.

The most conservative estimate of the war's cost comes from the non-partisan Congressional Budget Office (CBO), whose remit limits its analysis to US government spending. Up to Sept. 30, 2007, the end of the US's 2007 fiscal year, it says $413 bn was spent on Iraq. From then until end-2017, it calculates overall spending on Iraq and Afghanistan at $570 bn to $1,055 bn, depending on how quickly troop numbers are reduced. If three-quarters of the budget is spent on Iraq, the ratio of recent years, future direct budgetary costs would be a further $428 bn to $788 bn.

Interest payments on debt raised so far for the Iraq war would cost $290 bn up to 2017, with a further $131 bn to $218 bn covering spending over the next 10 years. This would bring the US government bill until 2017 for Iraq to $1,300 bn-$2,000 bn.

The JEC, chaired by Democratic Sen Charles Schumer of New York, tends to include economic costs to the US, such as the displacement of productive investment, interest paid to foreigners, and oil price increases, which add a further $700 bn so far. Until 2017, assuming US troop numbers in Iraq fall to 55,000 by 2013 and stay at that level, the cost grows to $2,800 bn in 2007 dollars.

A higher estimate comes in a new book, The Three Trillion Dollar War, by Nobel Prize winning economist Joseph Stiglitz and Harvard University lecturer Linda Bilmes, who was a senior official during the Clinton presidency in the 1990s. Stiglitz and Bilmes note more soldiers are surviving than in past wars because of better armour and medical care. Some 60,000 US troops have been air-lifted home, wounded, injured, or seriously ill. The ratio of combat injuries to combat deaths was 2.6:1 in Vietnam; in Iraq and Afghanistan it is 7:1 and, including non-combat injuries, it rises to 15:1.

The two authors project that 791,000 troops from Iraq and Afghanistan will claim disability compensation and benefits, noting that 39% of the 700,000 troops who fought in the brief 1991 Gulf war claim disability. They estimate these costs from Iraq alone will be $371 bn to $630 bn. The extra costs to the defence budget - they estimate from $66 bn to $267 bn - come from the need to reset and replenish a military in which equipment has been used up at six to 10 times normal rates and human capital has been exhausted. Their government spending estimate for the war comes to $1,292 bn-$2,039 bn, rising to $1,754 bn-$2,655 bn if interest is added. To this, Stiglitz and Bilmes add social costs not paid by the government, including the loss of productive capacity of those killed or wounded and quality of life impairments. These, they estimate, would amount to $295 bn-$415 bn for Iraq and Afghanistan.

Finally, the two authors add macro-economic costs deriving from higher oil prices and other effects including the impact on the economy of higher interest costs. For Iraq and Afghanistan, they calculate this would come to between $187 bn and $1,900 bn. Yet, these estimates do not cover the cost outside the US (including the [pounds sterling]20.1 bn of budgetary and social costs they estimate will have fallen to the UK up until 2010). Ms Bilmes, who says the book leaves others to estimate the war's benefits, describes the book's "three trillion" headline number as very conservative. She notes that the US government spent $108m in 2007 on research into autism, a condition affecting one in 150 children, saying: "We spend that in 41/2 hours in Iraq. I'm sure, if they knew that, people would say it was wrong".