There is a view of neo-conservatives as a cabal of shadowy figures - cloistered in Washington think tanks, vastly influential but accountable to no one - that hoodwinked a dim-witted president into invading Iraq.
Robert Kagan, the movement's most eloquent spokesman, has a different conspiracy theory, in which the ideologues are victims. They were made into scapegoats, he alleges, by a public ashamed of having cheered on the invasion. 'A war which had overwhelming American support, and was voted 77-23 in the US Senate, suddenly became a plot by six or seven people,' says Kagan.
Not that the neo-cons have had it too rough. After the American defeat in Vietnam the war planners were shunned by their colleagues, and booed during public debates. But the architects of Operation Iraqi Freedom have generally escaped such opprobrium.
Indeed Kagan, at 50, is in his prime. A monthly columnist for The Washington Post and senior associate at the Carnegie Endowment think tank, he was one of the chief foreign policy advisers to Republican presidential candidate John McCain.
He is a typical neo-conservative in many respects, not least in his moral clarity and conviction that America should be prepared unilaterally to declare war to uphold its values. But the label is meaningless to Kagan, who argues that there is nothing neo, or new, about his philosophy. He considers himself part of a long tradition of foreign policymakers who stress the importance of US global leadership.
In his 2006 book Dangerous Nation - the first of a projected two-volume history of US foreign relations - Kagan attempted 'to disprove the idea that America is traditionally an isolationist nation that only occasionally heads off into the world'. Some reviewers charged him with revising history to legitimise the neo-con vision of an imperialist America.