According to US Army officers in Iraq, the Pentagon has not sent enough troops to wage the war against Baghdad.

Army commanders compare Defence Secretary Donald H Rumsfeld to Robert S McNamara, the architect of the Vietnam War who failed to grasp the political and military realities of Vietnam, The New York Times said on Monday.

"He [Rumsfeld] wanted to fight this war cheap. He got what he wanted," the newspaper quoted a colonel as saying.

Last week, Lieutenant General William S Wallace, the V Corps commander, fired the opening salvo against the Pentagon when he said that the military faces the possibility of waging a longer war than had been anticipated by many strategists.

"The comments echo the tension in the bumpy relationship between Rumsfeld and General Eric K Shinseki, the army chief of staff," the daily said.

Currently, there are about 100,000 coalition troops inside Iraq, part of more than 300,000 on land, at sea and in the air.

According to the report, some of Rumsfeld's advisers now acknowledge that they misjudged the scope and intensity of resistance from Iraqi paramilitaries in the south, and forced commanders to divert troops already stretched thin to protect supply convoys and root out Saddam Hussein loyalists in Basra, Nasiriya and Najaf.

However, the report said that the advisers also point to the air campaign's successes in the past few days in "significantly weakening" the Republican Guard divisions around Baghdad.

"It was a painful process to match political and military goals," one senior official was quoted as saying.