"A series of strategic errors by the Bush Administration in its War on Terror has left Iran holding virtually all the cards in the power play of the Middle East, according to a report by Britain's most influential think-tank published today.
The report from the Royal Institute of International Affairs at Chatham House - entitled Iran, its neighbours and the regional crises - paints a bleak picture of the prospects for the United States and its Western allies as they try to put a cap on Iran's nuclear programme.
It describes Iran as a state that sits with "confident ease" in the region and says, crucially, that Iran has replaced the United States as the most influential power in Iraq, able to influence events on the street and not just behind the security barricades of Baghdad's Green Zone.
"There is little doubt that Iran has been the chief beneficiary of the War on Terror in the Middle East," says the report from Chatham House's Middle East Programme.
"The United States, with coalition support, has eliminated two of Iran’s regional rival governments - the Taleban in Afghanistan in November 2001 and Saddam Hussein’s regime in Iraq in April 2003 - but has failed to replace either with coherent and stable political structures."
The Chatham House experts wrote that their original report was to analyse Iran's regional influence in the context of international efforts to prevent it developing nuclear weapons.
Its scope was also to encompass the complexities of Iranian domestic politics and the clash between the "apocalyptic world-view" of President Ahmadinejad and the more pragmatic, conservative Supreme Leader, Ayatollah Ali Khamenei.
But as the conflicts grew in Gaza and the Lebanon, where Iran is the key backer of the Hezbollah militia, the 50-page report was expanded to consider all other inter-connected regional crises.
"A recurring theme is the desire of most states to maintain good relations with Iran or, where the relationship is less strong, to avoid antagonisation or any further deterioration," the report says.
"There exist a variety of reasons for this which have generally been strengthened by the turmoil in Afghanistan, Iraq, Palestine and Lebanon. Iran is in a powerful regional position and its co-operation and positive influence are needed to douse the many fires currently alight.
"Were Iran to feel seriously threatened by outside forces, it does have the potential to inflame the region yet further.""