Washington ? As Americans who oppose a war on Iraq gear up for national protests today and Sunday, activists say they are just starting to find their voice and flex their muscle, and that their coalition is much more diverse than the early opponents of U.S. military action in Vietnam.

Although it’s too early to tell whether they will become a potent political force, activists have persuaded 43 city councils to adopt antiwar resolutions, paid for a full-page ad in The Wall Street Journal, circulated petitions via the Internet and drawn growing numbers of demonstrators nationwide.

The protesters are diverse, decentralized and disagree on some issues. They include longtime pacifists, Persian Gulf War veterans, people who think President Bush stole the 2000 election, people who voted for him, kids with purple hair, CEOs, labor organizers, academics, churchgoers, even the inevitable soccer mom.

“Many of us think this rush toward war is crazy, and there is great urgency to stop it,” said Jane Hyde, 43, a suburban “soccer mom” in Orinda, Calif. “Some of the people involved have overlapping issues and don’t agree about some things, but we all agree about this war.”

Retired Vice Adm. Jack Shanahan of Ormond Beach, Fla., recently signed a full-page Wall Street Journal ad, a “dissent on Iraq” organized by Republicans and business leaders.

“Iraq represents no threat today to national security that warrants a pre-emptive invasion,” said Shanahan, a 37-year Navy veteran who served in three wars. “In war, you kill people and break things. There ought to be a better way.”

Thousands of antiwar demonstrators are expected this weekend in Washington and San Francisco. Their benchmark for size is 100,000, the estimated crowd at a similar march in Washington last October.

“What’s happened recently impresses me as fairly mainstream — unions and churches, for example,” said Todd Gitlin, a sociologist and author who has studied protest movements. “It’s like many movements — sloppy, decentralized, diffuse — but that’s not necessarily a weakness.”

Antiwar organizers, aided by the Internet, say they’re beginning to organize online petition drives, letter-writing, teach-ins on campuses and in churches, and protests at traffic intersections.

“I’ve noticed a remarkable diversity at events, from leftists to some conservatives,” David Fox said of protests he’s joined in the Minneapolis-St. Paul area.

Charley Richardson, a labor activist from Boston, went to a meeting last week in a Chicago Teamsters hall attended by 100 representatives of 60 union locals that have passed resolutions opposing an Iraq war.

Kansas University students Scott Pusich and Amanda Harrison protest a possible war with Iraq in this Sept. 24, 2002, file photo. Anti-war activists say their ranks are now more diverse -- and more influential -- than in previous decades.

“That would not have happened during the 1960s, and remember, so far not a single body bag has come back yet,” said Richardson, who marched against the Vietnam War.

Richardson and his wife, Nancy Lessin, have a personal stake in this cause. Their son Joe, an Arabic specialist in the Marines, is deployed in the Persian Gulf.

“We don’t speak for Joe, and we don’t want to get him in trouble,” said Lessin, who works for the AFL-CIO. “We send cookies and brownies, and we also fight to stop this war.”

The couple founded an organization, Military Families Speak Out, using a Web site to trade information with other families and oppose the war.

The Internet enabled Fox, a 33-year-old paleontologist at the University of Minnesota’s Twin Cities campus, to circulate his antiwar petition widely. He began at Minnesota and, with the help of colleagues, created a Web site that has attracted 33,000 signatures from campuses nationwide.

“It’s easy to organize on the Internet, but will people sign a petition and say that’s enough?” asked Fox. “It’s going to be difficult to measure effectiveness.”

He’s not optimistic.

“I don’t think we can stop this war, because that decision has been made,” Fox said. “But we can build a coalition and make sure the Bush administration suffers politically down the road for this.”

Hyde, who runs her husband’s medical office in California, is more upbeat: “People are more verbal now, and it’s acceptable to oppose this war. I hope we can stop it before it starts.”

Sara Iglesias, a Miami Beach writer who became a protest organizer last fall, said the movement had grown and broadened since then.

“Many participants are new — like me — and this is just starting to take off,” said Iglesias, 29, who arranged for four buses to take Floridians to the Washington demonstration.

Some activists concede they’re encountering resistance. When Hyde waved a “Soccer Mom Against War” sign at one rally, a driver screamed at her: “Go back to Berkeley.”

Richardson said one motorist threw pencils at him outside Boston. In Charlotte, N.C., police intervened on New Year’s Day when about a dozen veterans confronted 50 protesters at that city’s Vietnam Veterans memorial.

The protests are drawing Republican defectors. Ed Hamm, an oil executive and major Republican donor, helped plan the Wall Street Journal “dissent” ad. Liz Viering, who supported Bush and attended his inauguration, signed it.

“I don’t like what Bush is doing, and I think we’re being lied to,” said Viering, 50, who owns a real estate company in Stonington, Conn. “I have supported George Bush on other things, so maybe this will have more impact.”

Some war veterans also oppose war on Iraq. Erik Gustafson and Charles Sheehan-Miles, two Gulf War vets, organized Veterans for Common Sense, which has questioned Bush policy. Gustafson said about 400 veterans signed their statement.

“I killed a lot of Iraqis in the last war, and 12 (people) in my division were killed,” said Sheehan-Miles, a former tank crewman. “This time, I’m worried about urban warfare and a lot of casualties.”

Participants aren’t necessarily against the same thing. Some oppose any war against Iraq; others would back a U.N.-authorized military action to disarm Saddam Hussein.

A coalition called International ANSWER (Act Now to Stop War and End Racism) is organizing Saturday’s protests. ANSWER organizers, who last year sponsored pro-Palestinian rallies that featured harsh anti-Israel rhetoric, say the United States has become a dangerous force in the world.

One leader is Ramsey Clark, the former attorney general who has defended many radicals and Slobodan Milosevic, the former Yugoslav leader who is standing trial on war-crimes charges.

Hyde said she decided to leave a San Francisco march “when the anti-Israel dogma made me uncomfortable,” but she added: “That’s to be expected when different people come together like this.”

A more centrist group, United for Peace, is working with ANSWER, sometimes uneasily.

“ANSWER appeals more to the left, and I think we appeal more to the mainstream,” said Jason Kafoury, an organizer for United for Peace. “But we’re helping each other mobilize people. There are different groups and constituencies, but we have the same message: Stop the war.”