It is a war that will not end.

More than 31 years after the United States withdrew its last troops from Vietnam, the war and the domestic fight to end it remain a bramble of emotions and opinions still capable of snagging a presidential candidate.

The unresolved issues of the Vietnam War assumed the center of the political stage this week because it was 33 years ago that John Kerry, now the Democratic presidential candidate, made an appearance before the Senate Foreign Relations Committee that propelled him immediately and permanently into the nation's consciousness.

As a highly decorated veteran of Vietnam, Kerry told the senators in dramatic and eloquent terms that the war was corrupting the soldiers who were fighting it, devastating a country we were purporting to help and alienating the generation of Americans that were supposed to be doing the fighting.

Kerry told the senators the military men and women in Vietnam were being asked "to die for the biggest nothing in history. ... How do you ask a man to be the last man to die in Vietnam? How do you ask a man to be the last man to die for a mistake?"

It is a statement that resonates with a growing number of Americans who fear the war in Iraq is another foreign entanglement that will end badly.

As criticism of the Iraq conflict has mounted, leading Republicans have suggested that such comments undermine American efforts there and are an insult to the military personnel doing the fighting, an echo of the Nixon administration's attacks on antiwar protesters in the early 1970s.

Just weeks ago, Democrats eagerly questioned the details of President Bush's Vietnam-era service in the Air National Guard, drawing a contrast to Kerry's combat record.

"Here we are, going through the fifth presidential election in a row where at least one of the candidates on the national ticket -- his military record in Vietnam, or lack thereof -- has been a central part of the campaign," said political consultant Bill Carrick.

"It's one of those cultural Rorschach tests," Carrick said. "People who didn't serve, are they guilty about not serving? People who did serve, are they worried about the acceptance of their service? It's just a really complicated thing."

It is safe to say that Kerry's 1971 Senate testimony is at least one of the reasons he is now a 19-year U.S. senator from Massachusetts and the Democratic Party presidential candidate. And it's equally safe to say that he is an embodiment of the conflicting views about the war that still roil the American political scene.

As a graduate of Yale University, one of the nation's elite, he volunteered for the U.S. Navy and served in 1968-69 in Vietnam commanding a river patrol boat. He was wounded three times and decorated twice for heroism, once with the Bronze Star and once with the Silver Star, the nation's third highest medal for heroism.

Because he was wounded three times, Kerry eagerly accepted the option to cut short his tour of duty and return home. He did so, he has said in news interviews, because he was angered over what the war was doing to the men who were fighting it and because of his realization that the war was being fought in the wrong place for the wrong reasons.

He came home and co-founded Vietnam Veterans Against the War, which staged a high-profile march on Washington in 1971, the occasion that led to Kerry's Senate testimony.

Although by 1972, 60 percent of Americans saw the Vietnam War as a mistake, Kerry testified while the country was still badly divided on the issue.

"I thought Kerry had a huge impact on the antiwar movement," said the Rev. Scotty McLennan, at the time a divinity and law student and antiwar activist at Harvard University and now dean for Religious Life at Stanford University.

"The vice president (Spiro Agnew) was using terms like effete, impudent snobs," McLennan said. "We were undermining the war effort. We were not supporting our troops. Here you had this figure come forward from within the military and say the best way to support American values was to bring the troops home."

Carrick, who participated in antiwar demonstrations in the 1970s at the University of South Carolina, said Kerry's testimony had been "a seminal moment in the antiwar movement."

Now, 33 years later, with another war dominating another presidential campaign, the anniversary of Kerry's testimony is set against another uncertain political landscape.

In polls a year ago, more than 75 percent of Americans said the respective military experiences of Bush and Kerry made no difference to them.

But that was before the war in Iraq began and long before it became apparent that American involvement there would be neither swift nor tidy.

It took two years, from 1965 to 1967, for 41 percent of Americans to say it was a mistake to send troops to Vietnam, according to the Gallup Poll.

It has taken only one year for public opinion to reach the same level about Iraq. In a Gallup Poll taken a week ago, 42 percent of Americans say it was a mistake to send troops to Iraq.

As the Iraq war continues to gain importance as a presidential issue, Kerry's war record could enhance his credibility on foreign policy. But if he hopes to derive strength from his combat experience and his antiwar record, it could be an example of trying to have it both ways.

Republican political consultant Dan Schnur was communications director for the 2000 presidential campaign of Arizona Sen. John McCain, a decorated Vietnam prisoner of war, whose military credentials were a political asset.

"McCain's experience was the sort of thing that transcended partisan boundaries," Schnur said. "It didn't matter whether you were a supporter or an opponent of the Vietnam War. You could respect him for what he accomplished."

Some critics of Kerry have questioned whether he deserved the first of his three Purple Hearts, which prompted the Kerry campaign to issue an e-mail to supporters complaining about the Republican "ugly smear campaign on John Kerry's service. ... They're terrified of running against John Kerry's war record."

"It's never a good idea to question the legitimacy of someone's military service," Schnur said.

Indeed, Bush campaign spokeswoman Tracey Schmitt, asked about Kerry's war record, was careful to say, "We respect and honor Sen. Kerry's service as a young man." She then went on to attack Kerry's 19-year voting record in the Senate, which she described as abysmal on defense and on providing the financial support necessary to conduct the war in Iraq.

Kerry's war record is commendable, Schnur said, "but his role in the protests is much more divisive."

Frank Farley, a Temple University professor who studies the psychology of politics, said Kerry's dual positions on the Vietnam War -- supporting it enough to fight, then opposing it enough to protest -- had much to do with public perception of his personality, a deciding factor for many voters.

"It's so hard for the electorate to get into all the niceties of the issues, so we often fall back on personality qualities," Farley said. Kerry's Vietnam records could be seen as "inconsistent, shifting positions," a pattern critics could say is evident in his votes on Iraq, Farley said.

"I think some people already have a sense of that, although some of it is overridden by his heroism," he said.

But if the Iraq war drags on, and public opinion rises against it, "then his evolving stance will help," Farley said. "He will be riding that wave, whereas Bush will be inundated by it and gasping for breath."

E-mail Mark Simon at msimon@sfchronicle.com.

©2004 San Francisco Chronicle

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