The prime culprit for the plan, or lack of it, must be Donald Rumsfeld. He thought the GIs could march up to Baghdad, kick out Saddam and the bad guys, leaving the good guys to take over, and Johnny to come marching home. Rumsfeld simply lacked the intellectual vision and stamina, and covered this by a posture of cranky aggression.

Much the same might be said of Vice-President Dick Cheney, often seen as the eminence gris in this. Take a look at a clip from 1994 riding high at YouTube, in which a younger Cheney explains why the US forces had not gone to Baghdad to topple Saddam in 1991. His reasons are a perfect catalogue of indictment for his subsequent policies: America would have had to act alone, causing more casualties, the Arabs would have opposed, Iraq might have broken up and divided, and this would encourage the neighbours - Saudi, Syrian, Turk and Iranian - to more mischief.

But it wasn't just Don and Dick behind all this. Proconsul Bremer, egged on by the felon Ahmed Chalabi, broke the machine beyond repair by disbanding the army, purging Ba'athists, and so wrecking the civil service. Who was behind him? Bound by omerta, Douglas Feith, Paul Wolfowitz and Karl Rove all knew, but it was the other guy who decided. In the end the responsibility lies with the man theoretically in charge, George Bush, who fell for the neocon fantasy of a new America to lead a new world in a new century.

For the British generals there are now a series of questions that they may be unwilling or unable to answer. When did they realise all these terrible things about the malfunctioning senior ally? Did they mention it to the prime minister? If so, what was his response? According to the Alastair Campbell diary version of events, not much was discussed - Tony decided to go into Iraq with the Americans as far back as spring 2002. Gen Jackson and his fellow chiefs asked about the legality, and that was it. As I recall, the service chiefs were keen to go in at the time, and didn't like it when some of us suggested that this was no Northern Ireland: it was no simple case of soft berets and cups of tea.

Today the risk is that Bush, egged on by militants like Fred Kagan, Jack Keane and John Bolton, will go ahead and seek to solve one, or even two, wars by starting another - via a tactical strike on revolutionary guard units in Iran. Nothing allies, the UN or even Congress can do would stop them, because, in Bolton's phrase about Gen Jackson, "they do not understand the full picture". And for picture, read vision, for the last group of irreducibles are revealing the millenarian side of the neocon movement - theirs is a higher vision of the finality of things than the rest of us.

Gens Jackson and Cross have done us a service by speaking out. But they need to do more. They need to set down for the record the full range of their criticisms, and where, when and how they developed. For those now running the show, in fatigues or suits, they have to establish where today's misshapen Anglo-American alliance has got us in Iraq, Iran and Afghanistan - and how we can restore the normal commerce of international affairs and diplomacy. And it had better be very quick - before Cheney and co go kamikaze on Tehran.

Robert Fox is a senior associate fellow at the Centre for Defence Studies, King's College London robfox45@gmail.com