Divisions are emerging in the West’s united front towards Iran with fears being voiced over the aggressive military posture adopted by America, while European allies are accused by the US of dragging their feet.

A diplomatic source in Washington told The Times: “It is difficult to imagine Bush and Cheney leaving office without resolving the Iranian issue, if necessary, by force.”

Although the prospect of “precipitate action” by the US is discounted widely, some Western governments are said to be alarmed at events spiralling out of control.

Last week Mr Bush authorised US troops to “kill or capture” Iranians found operating inside Iraq’s borders. This week he reiterated that the US “will respond firmly” if Iran continues to interfere in Iraq. He emphasised that did not necessarily mean that he was planning to “invade Iran” and that the US is still pursuing a negotiated settlement through the United Nations to eliminate Tehran’s suspected nuclear weapons programme.

But there are fears that the tough new US approach, which included the arrest this month of five Iranian officials in the Iraqi city of Irbil, could trigger a new confrontation.

Reza Zakeri, the director of strategic studies in the Iranian president’s office, has said that Tehran might retaliate by capturing American soldiers.

“Abducting a US soldier in uniform is less expensive than buying a low-quality product made in China,” he said. “It would not be difficult to capture blond men with blue eyes wearing a military uniform. It would just be necessary to open a wallet and be generous.”

US Administration officials have expressed frustration with countries such as Britain, France, Germany and Spain whom they accuse of failing to isolate Iran financially. EU governments have provided the regime with billions of dollars in loan guarantees in recent years and have been slow to act against Iranian banks accused by the US of funding terrorism or financing missile programmes.

“Most European governments, particularly the UK, have no problem with stepping up pressure on Tehran,” said one diplomat yesterday. “But the US does appear to be on a shorter fuse than the rest of us. They want it all now.”

US intelligence believes that Iran has supplied charges, used by insurgents in roadside bombs to penetrate the thickest American and British armour. They have also distributed rockets, rocket-propelled grenades and ammunition as well as providing guerrilla training to Iraqi militias.

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