I’ve rarely seen a more revolting spectacle than that of George W. Bush — who, remember, dodged the Vietnam draft — lecturing his countrymen on the ‘lessons’ of Vietnam.

But it’s interesting that he was at least implicitly acknowledging that the Iraq fiasco is beginning to resemble the Vietnam adventure ( a comparison that nobody who’s ever read Barbara Tuchman’s The March of Folly would have missed). At the beginning of the Iraq adventure, Administration officials used to deny the validity of any such comparison.

Now comes a New York Times report of a new US Intelligence Assessment of the situation on the ground in Iraq.

WASHINGTON, Aug. 23 — A stark assessment released Thursday by the nation’s intelligence agencies depicts a paralyzed Iraqi government unable to take advantage of the security gains achieved by the thousands of extra American troops dispatched to the country this year.

References in the report to Al Qaeda in Iraq are to a homegrown Sunni Arab extremist group that American intelligence agencies have concluded is foreign-led.

The assessment, known as a National Intelligence Estimate, casts strong doubts on the viability of the Bush administration strategy in Iraq. It gives a dim prognosis on the likelihood that Iraqi politicians can heal deep sectarian rifts before next spring, when American military commanders have said that a crunch on available troops will require reducing the United States’ presence in Iraq.

But the report also implicitly criticizes proposals offered by Democrats, including several presidential candidates, who have called for a withdrawal of American combat troops from Iraq by next year and for a major shift in the American approach, from manpower-intensive counterinsurgency operations to lower-profile efforts aimed at supporting Iraqi troops and carrying out quick-strike counterterrorism raids.

Such a shift, the report says, would “erode security gains achieved thus far” and could return Iraq to a downward spiral of sectarian violence.

The real message of the report (available here in pdf) is that the US cannot go forward — and cannot go back). Which is not a bad working definition of a quagmire.

One of the more intriguing things about Tuchman’s analysis is how a weak and incompetent government — the Saigon administration — could effectively control a superpower, because the weaker the South Vietnam regime became, the more the US was sucked into propping it up. Now it’s becoming clear that the Iraqi government is incapable of running the country, and the Americans are experiencing the same pressures as they did in Vietnam. The main difference is that then the US had a conscript army (minus the draft-dodging contingent of Bush, Cheney, Rumsfeld, Wolfowitz, Perle, Clinton et al), whereas now it’s exploiting — and over-stretching — its professional forces.