A group of senior US military commanders have reportedly decided to resign, should the White House order a military strike against Iran.
The reports come as tension in the Persian Gulf region has raised fears that US President George W. Bush might order an attack on Iran before his term expires.
"There are four or five generals and admirals we know would resign if Bush ordered an attack on Iran," a source with close ties with British intelligence services said.
"There is simply no stomach for it in the Pentagon, and a lot of people question whether such an attack would be effective or even possible.”
A British defense source confirmed that there were deep misgivings inside the Pentagon about a military strike. "All the generals are perfectly clear that they don't have the military capacity to take Iran on in any meaningful fashion. Nobody wants to do it and it would be a matter of conscience for them.”
The threat of a wave of resignations coincided with a warning by Vice-President Dick Cheney that all options, including military action, remained on the table.
According to a report in The New Yorker magazine, the Pentagon has already set up a working group to plan air-strikes on Iran.
The panel initially focused on destroying Iran's nuclear facilities. However, army chiefs fear an attack on Iran would lead to a rise in oil prices and a full-blown regional war.