A senior US intelligence official has told the BBC that the American-led war in Iraq was "a gift of epic proportions to Osama Bin Laden".
The official argues that invading Iraq made the US no safer
The official, identified as Anonymous, is preparing to publish a new book which says that the US is losing the battle against the al-Qaeda network.
He told the BBC's Newsnight programme that the US needed to have a debate about its policies in the Middle East.
He said the military option alone was "a bloody and unsuccessful tool".
The official's book, Imperial Hubris, to be published in August, rejects the Bush administration's assertions that al-Qaeda is in retreat and that the war in Iraq has made the US safer.
The author, described as a senior official with 20 years' experience of national security and terrorism issues, told BBC television that Osama Bin Laden's followers were "a spreading movement, powered by religion and also grounded in opposition to American policies".
"Unless there's a debate in our country about changing those five or six policies Bin Laden is focused on, we will certainly bleed... in the foreseeable future, certainly decades ahead," he said in the Newsnight interview.
The official said Washington's support for tyrannical regimes, its unqualified support for Israel and its presence in Iraq and Saudi Arabia were all policies that should be debated.
The exclusive interview can be seen in full on Newsnight on BBC2 at 2230 BST on Tuesday, 13 July.