President Bush warned Americans today that a US withdrawal from Iraq could produce a catastrophe similar to the one that cost hundreds of thousands of lives in south east Asia after US forces left Vietnam in 1975.

In a speech in Kansas City to an audience of veterans, many of whom fought in Vietnam, Mr Bush said that an early exit from Iraq would "pull the rug out" from under American troops just as their efforts are paying off.

But in drawing a parallel between Iraq and Vietnam — a parallel which his Admistration has always avoided — Mr Bush angered many political opponents, who immediately questioned the accuracy of the comparison.

The speech marked the start of an attempt by Mr Bush to regain the initiative on Iraq before the top military and civilian officials report to Congress next month on the progress of the war and Iraq's political progress.

Expert View

The US spent two years negotiating with North Vietnam to end the war. In Iraq, formal negotiations have yet to begin

Michael Binyon

• More

• Post a comment

Related Links

• US hits out at Iraq government as moment of truth nears

• US envoy: the British have failed in Basra

• Washington puts pressure on Maliki

It was undermined, however, by news only a few hours before that 14 US soldiers had been killed in a helicopter crash in northern Iraq, the deadliest such incident for two years. The US military said that the Blackhawk helicopter had been downed by a technical malfunction.

Mr Bush told the national convention of the Veterans of Foreign Wars that his speech was intended to provide "some historical perspective" on the campaign against Islamic extremism around the world.

He celebrated the success of postwar reconstruction in Japan after the Second World War and the emergence of South Korea after its war with the North. Then he moved on to the more contentious example of Vietnam, arguing that the US withdrawal after nine years of conflict produced a bloody vacuum in Vietnam, Cambodia and Laos.

"There is a legitimate debate about how we got into the Vietnam War and how we left," he said.

"Whatever your position in that debate, one unmistakable legacy of Vietnam is that the price of America's withdrawal was paid by millions of innocent citizens whose agonies would add to our vocabulary new terms like 'boat people', 're-education camps,' and 'killing fields."

Mr Bush said another legacy of Vietnam was America's perceived unwillingness to be fight overseas again. "There was another price to our withdrawal from Vietnam, and we can hear it in the words of the enemy we face in today’s struggle," Mr Bush said.

The President quoted speeches by Osama bin Laden and his number two Ayman al-Zawahiri, who urged al-Qaeda supporters to remember "how they ran and left their agents" in Vietnam.

"We must listen to the words of the enemy," he said, arguing that the war on terror represented an ideological battle similar to that waged against imperial Japan and Nazi Germany.

Mr Bush's assertion that there remained a "legitimate debate" about America's involvement in Vietnam was the first thing to be questioned. One poster on the liberal Daily Kos weblog replied: "Sure — just like there's a 'legitimate debate' about the theory of evolution."

The President's reference to the "killing fields" of Cambodia was equally controversial. It was quickly pointed out that the Khmer Rouge seized power only after a failed American bombing campaign brought down the previous Cambodian government.

Harry Reid, the Democratic Senate Majority Leader, quickly dismissed Mr Bush’s sense of history.

"President Bush’s attempt to compare the war in Iraq to past military conflicts in East Asia ignores the fundamental difference between the two," he said. "Our nation was misled by the Bush administration in an effort to gain support for the invasion of Iraq under false pretences, leading to one of the worst foreign policy blunders in our history."

As Mr Bush insisted that America "must get the job done" in Iraq, a senior US General criticised what he described as the disengagement of British forces around Basra as the UK reduces its troop levels in Iraq.commitment.

General Jack Keane said that Basra was sliding into a state of "gangland wafare" just as the security situation was improving in central and northern Iraq. He said US commanders were unhappily facing the prospect of sending reinforcements to the south as the UK continues to reduce its force.

"I think there is a general disengagement from what the key issues are around Basra. I would imagine that is where the source of frustration is," he told the BBC. "The Brits have never had enough troops to truly protect the population and we (the Americans) have found that out painfully in the central region as well."

Times Recommends

• Should Knox’s trial even have reached the courtroom?
• 'Was it real?' The US bailout nightmare
• Iranian opposition plays the long game