A reunion of old hands from the Vietnam War is underway at the U.S. Embassy in Baghdad. It's almost become Saigon on the Tigris.

The new crowd running U.S. policy on post-occupation Iraq, in Baghdad and in Washington, all cut their teeth in Vietnam. The four top officials at the new U.S. Embassy in Baghdad are military or diplomatic veterans of the Vietnam War: Ambassador John D. Negroponte; James F. Jeffrey, the embassy's second in command; Ronald E. Neumann, an Arabic speaker who gave up an ambassadorship in Bahrain to take charge of political-military affairs; and William B. Taylor Jr., head of the new Iraqi Reconstruction Management Office.

Negroponte's second posting was to Saigon, where he was political officer and resident expert on Vietnam's constituent assembly in the early 1960s. It was good preparation for Baghdad, because Iraq's first election in January will be for a national assembly. The performance of that body, which is to craft a new constitution, will be a pivotal test for Iraq's transition.

Jeffrey was an Army platoon leader with the group advising Vietnam's special forces in the early 1970s. After the Army, Jeffrey joined the Foreign Service and specialized in conflict management and prevention, especially in the Middle East and the Balkans.

"Over these past 33 years, in and out of uniform, I have tried . . . to ensure that diplomatic action and military options were fully balanced, coordinated and complementary," he said in 2002 Senate confirmation hearings to become ambassador to Albania.

Neumann was awarded a Bronze Star as a young infantry officer in the late 1960s.

Taylor was a graduate of the U.S. Military Academy at West Point who served with the 101st Airborne in Vietnam. The Iraqi Reconstruction Management Office that he now heads is responsible for distribution of $18.4 billion in U.S. aid.

At home, the State Department's top two officials, who assumed control of U.S. policy on Iraq from the Pentagon after the June 28 transfer of political power, had their first jobs in Vietnam. Secretary of State Colin L. Powell served two tours in Vietnam as a young lieutenant. His deputy, Richard L. Armitage, became a counterinsurgency specialist after graduating from the U.S. Naval Academy in Annapolis. He served three combat tours in Vietnam.

In an interview with PBS's "Frontline," Powell reflected on the "Vietnam syndrome" in the U.S. military. "Does it affect our thinking? Sure, it was the most definitive military event in our lives and in our careers. But it is not a syndrome, as if it's some sort of mental disease we have. It's the right way to go about dealing with war: Have a clear objective, know what you're doing . . . know what you're trying to achieve," he said.

Some Vietnam veterans and analysts say the Vietnam experience of the post-Iraq occupation policy team is in marked contrast to the major Pentagon policymakers in charge during the war and yearlong occupation. Defense Secretary Donald H. Rumsfeld; Deputy Defense Secretary Paul D. Wolfowitz; Douglas J. Feith, undersecretary for policy; and Stephen A. Cambone, undersecretary for intelligence, have not served in a conflict environment. Rumsfeld served as a naval aviator in the 1950s.

The contrast has some policy insiders, Vietnam veterans and analysts abuzz over what difference it might make in Iraq.

"What the Vietnam experience brings is a realistic appreciation of the fact that war and the peacemaking process after a war are a messy, uncertain, chaotic process," said John F. Guilmartin Jr., an Ohio State University military historian who flew 120 combat missions in Vietnam, as well as a helicopter evacuation flight during the fall of Saigon.

"They go in with a certain caution -- it's instinctive -- and they'll be much more inclined to look at the worst-case scenario and plan around it," he added.

Retired Army Gen. Barry McCaffrey, West Point's distinguished professor of international security, who was awarded three Purple Hearts in Vietnam, said: "Part of the story is who didn't serve in Vietnam and wasn't affected by that great policy tragedy, namely Rumsfeld. He never saw the confusion, bloodshed and lack of a clear national objective involved in ground combat operations in a foreign country."

McCaffrey added: "Whereas when you look at Powell and Armitage and others, as young men they saw firsthand the results in shattered lives and failed policies of the Washington elite who couldn't listen to their own internal feedback mechanisms. That provides astonishing insight."

Asked about the contrasting lack of combat experience at the top of the Pentagon's civilian leadership, Bryan Whitman, a senior Defense Department spokesman, said: "It is a curious observation that doesn't seem to be particularly relevant.

"Everyone has brought their experiences to the table in the execution of U.S. government policies in Iraq. It would be inappropriate to view operations in Iraq as anything other than a government-wide effort."

The specter of Vietnam, nonetheless, could make the next phase of U.S. involvement in Iraq look significantly different, some U.S. military analysts say.

"From Vietnam, one thing burned into our souls is that just winning the battles is not enough. We did that in Vietnam. We could take any piece of terrain and defeat the forces in the field. But it wasn't enough," said retired Marine Gen. Anthony C. Zinni, former head of Central Command. "In Iraq, it's exactly the same problem. It's: Are we improving our environment, and are we providing security and protection for the people and infrastructure?"

The emergence of a generation of Vietnam veterans as important players in Iraq comes as the Vietnam War has emerged as a major issue in U.S. politics, partly because of Iraq but also because it defines a personal difference between the two major presidential candidates. President Bush did not serve in Vietnam; Sen. John F. Kerry (D-Mass.) did.

The Bush administration is intent on avoiding comparisons of U.S. policy in Iraq with Vietnam, in part to avoid the implication that Iraq also will become an unwinnable quagmire. "Neither Ambassador Negroponte nor Jim Jeffrey has the time to discuss, or sees any connection between, their experience of 30 to 40 years ago in Vietnam and what they are doing today," embassy spokesman Robert Callahan said in an e-mail.

But State Department officials acknowledge that they looked closely at the Vietnam era in creating and staffing the new embassy, the largest in U.S. history.

"In preparing the new embassy, we looked at historic cases in which we had both a large military presence and a large embassy for lessons learned about how you can manage the two in a productive way and avoid conflict. Vietnam was definitely an important example," said a senior State Department official, who spoke on the condition of anonymity.

Vietnam experience will also be valuable in avoiding some of the fatal aspects of U.S. policy in that war, particularly Washington's relationship with the South Vietnamese government, U.S. officials say.

"Maybe it's Vietnam, maybe it's just common sense, but Negroponte has been outspoken about giving the new Iraqi interim government space to do its thing and not suffocating it with too strong an embrace," the State Department official added. "In South Vietnam, the question was whether the government was just a puppet of the United States. In contrast, Negroponte is saying we're not in Iraq to be an imperial overlord."

U.S. officials also hope the diplomats' Vietnam experience will ease the tensions that often characterized relations between U.S. commanders and the Coalition Provisional Authority during the occupation. Citing his Vietnam stint, Negroponte said during his April confirmation hearings before the Senate Foreign Relations Committee that he is "no stranger to the question of working on a teamwork basis with our colleagues in uniform."

"One of the lessons in looking at past experiences was that you have to have close and good personal relations between the embassy and the military," added the State Department official. "You have to be communicating well and understanding their mission and coordinating all the time. This is where this group's experience is really going to pay off, in that they understand the constraints and imperatives of the military. That sensibility, that sensitivity will go a long way to ensure smoothness and synchronicity."

Staff writer Thomas E. Ricks contributed to this report.

The new U.S. ambassador to Iraq, John D. Negroponte, and his second-in-command, James F. Jeffrey, right, walk the grounds of the U.S. Embassy in Baghdad for the first time in June. The four top officials at the new embassy are military or diplomatic veterans of the Vietnam War.