Army Lieutenant Colonel Antulio Echevarria presented his findings in a report published last month by the US Army War College, which made a point of saying the study presented only the views of its author.

Echevarria said military operations designed to bring about regime change usually require a labor- and time-intensive effort.

But the administration of President George W. Bush, he argued, was driven by "the desire to win the war quickly and on the cheap."

It downplayed the possibility that the overall financial cost of the conflict would be high and even dismissed chief White House Economic Adviser Lawrence Lindsay, who had projected the conflict could cost between 100 billion and 200 billion dollars, according to the report.

"It lowballed the number of US troops and other personnel that might have to be put in harm's way to get the job done, and how long they might have to remain deployed," the scholar wrote.

The analysis echoes warnings issued early last year by then Army chief of staff General Eric Shinseki, who told Congress several hundred thousand troops would be needed in post-war Iraq.

In a rebuke, Deputy Defense Secretary Paul Wolfowitz said the projection was "wildly off the mark," and Shinseki was sent into retirement soon thereafter.

Congressional critics have repeatedly stated since then that the Shinseki analysis was correct and accused the administration of feeding the public unrealistic rosy forecasts.