After Pat Duquette returned to New York from marching on Washington last month, her husband of 10 years was upset. A supporter of U.S. intervention in the Persian Gulf, he had not wanted her to participate in an anti-war demonstration.

Frank Duquette wondered whether the difference of opinion might threaten his marriage. His wife, a 42-year-old paralegal and mother of three, had never before participated in a protest of any kind.

Duquette's 20-year-old son, Jonathan Hutter, too had told his mother, "I can't support you," when she told him about the march. Although he was against the war before it started, he had changed his mind and believes that anti-war demonstrations demoralize and endanger the troops. Only Pat Duquette's 19-year-old daughter endorsed her mother's position. Their 9-year-old son was silent.

"There is so much at stake with the war," Pat Duquette said. But "you don't want to ruin all the relationships you have."

This is the other battlefield in the war, the conflict at the home front, where families engage every day in potentially explosive discussions about the U.S. role in the gulf. According to a Washington Post-ABC poll conducted Feb. 1 through Feb. 5, one of every seven families is divided by the war.

As the ground war has become more imminent and with it the possibility of a large number of casualties, divisions in families are becoming more stark and harder to ignore, many said.

"It's going to tear the country apart," said Pat Duquette. "I see it in my own family."

After she returned from the march, her husband was disturbed further when she announced plans to counsel youths on becoming conscientious objectors. There wasn't a draft, he said, and Americans have an obligation to fight if their country calls.

"You can't have a fantasy you can stop the war by yourself," he pleaded.

The Duquettes, like many families, have learned to "mutually exist," Pat Duquette said. "I have learned to constrain myself." Her husband too has softened his position as ground war -- a step he believes would be a "major mistake" -- has appeared likely.

Others simply have turned away from the heavy television coverage. "We don't even watch it anymore. And we don't watch commercials," said Harry Vitale, 62, a New Jersey butcher whose wife and 20-year-old son disagree with his support for the U.S.-led coalition against Iraq.

Elsewhere, others are worried about the war's effect on families. Family therapist Judy Clair said she met "an enormous amount of resistance" at one Northern Virginia school's parent-teacher meeting when she tried to encourage parents to come up with a "family perspective" and to develop "some commonality about their beliefs" on the war to help their children.

Ari Isenstadt, 22, a research assistant at Johns Hopkins University Hospital in Baltimore, recently asked his 25-year-old brother, an Air Force pilot stationed in South Carolina, whether he was jealous of others in his squadron who had been sent to Saudi Arabia. When his brother responded that he was, Isenstadt said he replied: "What are you jealous of? That they are killing people?"

Aware that their mother was worried their differences might tear apart the family, Isenstadt said, he and his brother assured her this "has not become a civil war and is not going to become a civil war." Still, Isenstadt acknowledges, "if my brother goes over and kills someone, it might change things."

Conflict within families is hardly new. Divorce rates in recent years attest to that. And families have splintered over previous wars. But the dissension has taken on a different hue here, therapists and historians suggest.

Unlike the Vietnam War era, when the ideological division often was along generational lines, those differing about this war are almost as likely to be mates as parent and child.

Of those surveyed who said there was family conflict over the war, 38 percent said they disagreed with their spouse. Of those interviewed more extensively about their differences, the wife almost always opposed the war and the husband supported it, reflecting the well-documented gap between the sexes on the war.

"I think men have a cowboy-and-Indian syndrome," said Debra Walsh, 25, of Youngstown, Ohio, who disagrees with her husband and her father. "My father said I'm a communist and I belong in Russia," she said.

Woodrow Dubose, 38, a Vietnam veteran from Paterson, N.J., said he was surprised when his wife, Joyce, vehemently disagreed with him as television news described the outbreak of war. "She usually listens to what I have to say," he said.

Family therapist Charles Figley cautioned against assuming that families in conflict over the war are, in general, families in conflict. "These are not bad marriages; these are not dysfunctional marriages," said Figley, who is chairman of the Presidential Task Force on the Persian Gulf Crisis for the American Association of Marriage and Family Therapy.

Until the war, Pat Duquette, who lives in Westchester County, said she and her husband regularly argued about politics. He's a Republican. She's a Democrat. He voted for President Bush, and she for Michael Dukakis. Their arguments were heated, but when the debate was finished, the argument was gone. This time it was different.

Frank Duquette realized his wife had never felt so passionately about anything in her life -- "she thinks she's the mother of all the world's children" -- but he felt her position could be harmful to the troops.

"It was the first time in our marriage -- on something that was not related to Pat or I as an issue -- that we were on opposing sides," he said.

Splits are particularly painful in families with military connections. Clair, the family therapist, who runs a support group for people with relatives or friends in the gulf, said many participants have conflicting feelings about the war and are afraid to speak for fear of appearing disloyal.

Despite her position as a spokeswoman for the American Association of Marriage and Family Therapy here, Virginia Rutter was unable to avoid a conflict with her mother. She said her mother feels she "dishonored the memory of my brother," a Navy officer who died in a plane crash five years ago, by attending anti-war rallies. "We've talked superficially since then," she said.

"I think this war will definitely change things for my family," Rutter said. "We disagree on politics all the time, but it's closer to the bone because it's an issue you cannot leave on the corner of the coffee table."

The Duquettes believe some good may come out of their conflict, for their 9-year-old son. "I'm hoping he'll grow up believing people can have a difference of opinion and still respect each other," Pat Duquette said.