WASHINGTON, May 20: US action in Iraq could prove a foreign policy debacle if the Bush administration ignores Washington's painful failure at nation-building in South Vietnam a generation ago, a new Army report warns.

As in Southeast Asia, the United States is trying to fashion a legitimate state in Iraq against a backdrop of insurgency, rising US death tolls and tenuous support at home, said the report published this month by the Army War College.

But US troops, viewed by many Iraqis as invaders, lack the advantage of South Vietnam's large domestic security force as they seek to build new institutions under the pressure of a June 30 deadline for transfer of sovereignty.

"In Vietnam, we were trying to prop up a government that had little legitimacy. In Iraq, we're trying to weave together a government and support it so it can develop legitimacy. Both are extremely hard to do," said co-author W. Andrew Terrill, of the War College's Strategic Studies Institute.

The Vietnam War, a Cold War catastrophe that still haunts American policymakers, ended in the 1970s with 58,000 US war dead after public opinion turned against policies aimed at containing Communism in Southeast Asia.

Administration officials have rejected assertions Iraq, now a main front in the US "war on terrorism", poses a Vietnam-like quagmire for the 135,000 US troops now inside the country.

Terrill and his co-author, Air Force War College professor Jeffrey Record, say there are few military parallels between Iraq and Vietnam, where Communist fighters backed by the Soviet Union and China defeated a peak force of 500,000 US troops.

But their 69-page report, titled "Iraq and Vietnam: Differences, Similarities and Insights," warns of dire consequences if the political lessons of Vietnam go unheeded. "Repetition of those failures in Iraq could have disastrous consequences for US foreign policy," it says.

Terrill and Record warned of potentially dangerous political damage to US-Arab relations if Washington's objective of installing democracy in Iraq means the establishment a large American military presence in the region.

The War College says the report does not necessarily reflect the views of the Army, Pentagon or US government. Given that Iraqis have known nothing but authoritarian rule since the country's inception, it's impossible to say whether US policy will succeed, the authors say. -Reuters