Most senior US military officers now believe the war on Iraq has turned into a disaster on an unprecedented scale.

'Bring them on!" President Bush challenged the early Iraqi insurgency in July of last year. Since then, 812 American soldiers have been killed and 6,290 wounded, according to the Pentagon. Almost every day, in campaign speeches, Bush speaks with bravado about how he is "winning" in Iraq. "Our strategy is succeeding," he boasted to the National Guard convention on Tuesday.

But, according to the US military's leading strategists and prominent retired generals, Bush's war is already lost. Retired general William Odom, former head of the National Security Agency, told me: "Bush hasn't found the WMD. Al-Qaida, it's worse, he's lost on that front. That he's going to achieve a democracy there? That goal is lost, too. It's lost." He adds: "Right now, the course we're on, we're achieving Bin Laden's ends."

Retired general Joseph Hoare, the former marine commandant and head of US Central Command, told me: "The idea that this is going to go the way these guys planned is ludicrous. There are no good options. We're conducting a campaign as though it were being conducted in Iowa, no sense of the realities on the ground. It's so unrealistic for anyone who knows that part of the world. The priorities are just all wrong."

Jeffrey Record, professor of strategy at the Air War College, said: "I see no ray of light on the horizon at all. The worst case has become true. There's no analogy whatsoever between the situation in Iraq and the advantages we had after the second world war in Germany and Japan."

W Andrew Terrill, professor at the Army War College's strategic studies institute - and the top expert on Iraq there - said: "I don't think that you can kill the insurgency". According to Terrill, the anti-US insurgency, centred in the Sunni triangle, and holding several cities and towns - including Fallujah - is expanding and becoming more capable as a consequence of US policy.

General Odom said: "This is far graver than Vietnam. There wasn't as much at stake strategically, though in both cases we mindlessly went ahead with the war that was not constructive for US aims. But now we're in a region far more volatile, and we're in much worse shape with our allies."

General Odom remarked that the tension between the Bush administration and the senior military officers over Iraqi was worse than any he has ever seen with any previous government, including Vietnam. "I've never seen it so bad between the office of the secretary of defence and the military. There's a significant majority believing this is a disaster. The two parties whose interests have been advanced have been the Iranians and al-Qaida. Bin Laden could argue with some cogency that our going into Iraq was the equivalent of the Germans in Stalingrad. They defeated themselves by pouring more in there. Tragic."