Sambrook, who is director of the BBC's global news division, said that as a consequence American news media failed to do its job.
"Before Iraq, it seemed to me that some US news broadcasters wrapped themselves in the flag and, as a consequence, did not perform the role the public expects of them.
"I understand the problem. The mindset of the country was that it was at war. Our natural instinct is to support our country," he said.
Sambrook said that the overly patriotic got in the way of the press's responsibility to ask the difficult questions, such as those that needed to be asked about weapons of mass destruction in Iraq.
"The responsibility of the news media is to ask the difficult questions, to press, to verify. And we now know that all of us failed to ask the right questions about WMD in advance of the war," he said.
The BBC paid a heavy price for its war in Iraq, losing its chairman Gavyn Davies and director-general Greg Dyke, following the Hutton Report into the death of weapons expert Dr David Kelly, which heaped blame on the BBC and not the government.
Sambrook was clear not to pass judgment on the war itself, arguing that it was up to each to reach their own conclusions about that, based on precise information provided by the media.
"But to do so, they need accurate information, evidence that has been tested. And if a news organisation imbues itself with patriotism, it inhibits itself from asking some of those questions," he said.
His comments echoed those of Dyke last year who warned of the danger of broadcasters mixing patriotism and journalism. Dyke said it had already undermined the US media.
Dyke was responding in part to criticism of the BBC's coverage of the war in Iraq, where the corporation was accused of pro-Iraqi coverage and of failing to support British troops.
At one point, the Royal Navy axed the BBC's rolling news channel News 24 aboard the aircraft carrier HMS Ark Royal following complaints from the crew.
Sailors aboard the Navy's flagship were angered by the BBC's coverage of the war, particularly following comments made after the loss of two Sea King helicopters, which the BBC suggested was due to poor maintenance levels.
However, Dyke said that "if Iraq proved anything, it was that the BBC can not afford to mix patriotism and journalism".
He added: "This is happening in the US and, if it continues, will undermine the credibility of the US electronic news media."
Sambrook made his comments last night during the annual Poliak Lecture, hosted by the Graduate School of Journalism at Columbia University in New York, which also saw the announcement of a new committee on journalist safety. Almost 90 journalists and support staff have been killed in the past year, most in Iraq.
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