The blistering critique, by Brigadier Nigel Aylwin-Foster, who was the second most senior officer responsible for training Iraqi security forces, reflects criticism and frustration voiced by British commanders of American military tactics.

What is startling is the severity of his comments - and the decision by Military Review, a US army magazine, to publish them.

American soldiers, says Brig Aylwin-Foster, were "almost unfailingly courteous and considerate". But he says "at times their cultural insensitivity, almost certainly inadvertent, arguably amounted to institutional racism".

The US army, he says, is imbued with an unparalleled sense of patriotism, duty, passion and talent. "Yet it seemed weighed down by bureaucracy, a stiflingly hierarchical outlook, a predisposition to offensive operations and a sense that duty required all issues to be confronted head-on."

Brig Aylwin-Foster says the American army's laudable "can-do" approach paradoxically led to another trait, namely "damaging optimism". Such an ethos, he says, "is unhelpful if it discourages junior commanders from reporting unwelcome news up the chain of command".

But his central theme is that US military commanders have failed to train and educate their soldiers in the art of counter-insurgency operations and the need to cultivate the "hearts and minds" of the local population.

While US officers in Iraq criticised their allies for being too reluctant to use force, their strategy was "to kill or capture all terrorists and insurgents: they saw military destruction of the enemy as a strategic goal in its own right". In short, the brigadier says, "the US army has developed over time a singular focus on conventional warfare, of a particularly swift and violent kind".

Such an unsophisticated approach, ingrained in American military doctrine, is counter-productive, exacerbating the task the US faced by alienating significant sections of the population, argues Brig Aylwin-Foster.

What he calls a sense of "moral righteousness" contributed to the US response to the killing of four American contractors in Falluja in the spring of 2004. As a "come-on" tactic by insurgents, designed to provoke a disproportionate response, it succeeded, says the brigadier, as US commanders were "set on the total destruction of the enemy".

He notes that the firing on one night of more than 40 155mm artillery rounds on a small part of the city was considered by the local US commander as a "minor application of combat power". Such tactics are not the answer, he says, to remove Iraq from the grip of what he calls a "vicious and tenacious insurgency".

Brig Aylwin-Foster's criticisms have been echoed by other senior British officers, though not in such a devastating way. General Sir Mike Jackson, the head of the army, told MPs in April 2004 as US forces attacked Falluja: "We must be able to fight with the Americans. That does not mean we must be able to fight as the Americans."

Yesterday Colonel William Darley, the editor of Military Review, told the Guardian: "This [Brig Aylwin-Foster] is a highly regarded expert in this area who is providing a candid critique. It is certainly not uninformed ... It is a professional discussion and a professional critique among professionals about what needs to be done. What he says is authoritative and a useful point of perspective whether you agree with it or not." In a disclaimer he says the article does not reflect the views of the UK or the US army.

Colonel Kevin Benson, director of the US army's school of advanced military studies, who told the Washington Post the brigadier was an "insufferable British snob", said his remark had been made in the heat of the moment. "I applaud the brigadier for starting the debate," he said. "It is a debate that must go on and I myself am writing a response."

The brigadier was deputy commander of the office of security transition for training and organising Iraq's armed forces in 2004. Last year he took up the post of deputy commander of the Eufor, the European peacekeeping force in Bosnia. He could not be contacted last night.