The removal of Saddam Hussein could have been secured at a fraction of the cost of the Iraq war by paying him to go, a UK academic has suggested.
Saddam should have been made an offer he couldn't refuse
Military action will have cost $260bn (£144bn) by the end of 2006, says Prof Keith Hartley, of York University's Centre for Defence Economics.
"America could have given Saddam $20bn (£11bn) to go, $50bn to Iraq and still have had billions left over," he said.
A White House spokesman told BBC News the idea was "a ridiculous notion".
Prof Hartley's comments were made in a lecture on the costs of the Iraq War at the University of the West of England in Bristol on Thursday.
He said: "Wars are not cheap and quite often costs are ignored in debates about war.
"But one solution would have been to make Saddam Hussein an offer he couldn't refuse to go.
"The UK would not have been involved, no-one would have died and no buildings would have been destroyed.
"People would say that involves rewarding a dictator, but what is the moral authority for going to war with the huge loss of life that it involves?"
A US official at the White House told BBC News: "It is a ridiculous notion that we could have paid Saddam Hussein to leave Iraq.
"He did not need any more money, as he had clearly stolen huge amounts from the Iraqi people.
"President Bush gave Saddam every opportunity to leave Iraq as he made clear on 17 March 2003 when he gave him 48 hours to go."
Prof Hartley calculates that the total cost of the conflict to the US, UK, Iraq and other nations is likely to be more than $1.25 trillion.
That figure includes the estimated $1 trillion impact on world economic output of higher oil prices prompted by the conflict.
He suggested that the scale of the expenditure should prompt a major re-assessment of Britain's military role.
"If we are going to continue our role as a world military power, we can't ignore the economics," he said.
"The cost of equipment and personnel are rising and something has to give.
"We could abandon our role as a world military power leading to considerable savings on our defence budget, probably of the order of 0.5% of gross domestic product a year."