dubya blair
© Kevin Lamarque / ReutersU.S. President George W. Bush (L) and British Prime Minister Tony Blair walk together from their meeting at the U.S. Embassy in Brussels, February 22, 2005
Despite wishing to appear as America's top ally, Britain exerted no influence whatsoever over US aims in Iraq and merely ended up being a "second class" partner with no say in planning or policymaking, according to one of the UK's most senior diplomats.

Sir Jeremy Greenstock, a former UK ambassador to the UN, sets out his arguments in a new book titled 'Iraq: the Cost of War' and a lengthy interview with the Guardian.

The book had been due for publication in 2005 but was held back for more than 10 years after complaints by Jack Straw - the controversial Blair-era foreign secretary who was criticized in the Chilcot report into the Iraq War.

"We were in the second-class carriage not driving the engine," Greenstock said, arguing that US authorities viewed the Iraq invasion as "an American project in every sense that mattered and only Americans - and the right Americans at that - were qualified to conduct it."

He also said the "predatory emergence" of Al-Qaeda, and later Islamic State (IS, formerly ISIS/ISIL), in the region was "made far more likely by the survival of [ISIS leader] Abu Bakr al-Baghdadi in Iraq and by the battle-hardening experience of the resistance there."

He said that far from bolstering America's place in the world, the war had done huge damage. "To most people on the planet now it is unacceptable for the US on its own to interpret international legitimacy.

"America's pure moral authority is no longer greater than if it was a small island state," Greenstock said.

The conflict also continues to inform politics in the UK - even encouraging the isolationist Brexit vote - due to "the British public's distaste for the Iraq War," he added.

"Throughout the whole Iraq saga the UK never had a significant impact on US policy formulation," he told the Guardian.

"America will make its decisions on American advice, within American procedures and politics. They do not close doors, but they do not open the doors where the final decisions are made. It would not have occurred to [former US Secretary of Defense] Donald Rumsfeld to consult the British every time he took a corner on the road."