The last time Robert Young participated in a demonstration, he was protesting the Vietnam War as it wound down.

It took more than 30 years to make it happen again, but yesterday Young joined hundreds of others on the Mall to support the nation's troops in Afghanistan and Iraq, among them his son, Croft, 32.

"I'm a quiet person," said Young, 65, who traveled from Atlanta toting a full-size Marine Corps flag. "I don't really believe in demonstrations, but I wanted to come here to support my son," a Marine who left Camp Pendleton, Calif., on Wednesday for Fallujah, Iraq.

The afternoon rally was tiny in comparison with Saturday's antiwar demonstration, for which D.C. Police Chief Charles H. Ramsey gave a crowd estimate of at least 100,000. But undeterred participants waved flags and placards adorned with such slogans as "Keep the Promise to Iraq" and cheered for the dozens of speakers, many of whom denounced antiwar activist Cindy Sheehan, the mother of a soldier killed in Iraq.

Deborah Johns, the mother of an Iraq war veteran, has been traveling across the country speaking in support of the war. She directed some of her comments yesterday at Sheehan, saying that she speaks neither for Johns nor the American people.

After praising President Bush, Johns said she knew what she'd like to do with Sheehan and the antiwar protesters who descended on Washington on Saturday: "I'd like to ship them to Iran." The comment earned applause.

The rally was largely peaceful, punctuated by a few small clashes with antiwar protesters, one of whom wore a T-shirt that read: "Wanted for Mass Murder: The Bush Regime."

Rally-goers asked police to remove the man, who went limp as officers came to escort him away.

"Saddam Hussein is a moron, and you're a moron!" came a voice from the crowd.

"I'm a patriot," responded the protester, who peacefully followed police off the Mall sipping from a Starbucks coffee cup. "Look what's happening. I'm being taken from a public park because of a T-shirt."

By 1 p.m., a small band of antiwar demonstrators had lined up behind the rally stage to deliver such chants as "Hey, Bush, whaddaya say? How many kids have you killed today?"

Other antiwar activists spread out across the city.

In the ballroom of a Holiday Inn on Capitol Hill, about 350 "jurors" sipped coffee and ate desserts as they watched a mock trial of Defense Secretary Donald H. Rumsfeld, former CIA chief George J. Tenet and U.S. Attorney General Alberto R. Gonzales. The men were accused of violating U.S. law and the Geneva Convention in supporting torture.

"Obviously, this isn't a real court of law," said Jennifer Harbury, a coordinator of the program. "I don't expect Mr. Rumsfeld to show up here and answer questions."

But a younger and thinner Rumsfeld, played by human rights activist and actor David Clennon, did answer questions, drawing laughs from the audience with the line: "Torture is simply -- it's un-American." It was a paraphrase of a statement by Rumsfeld.

A few blocks away on the Mall, about 200 people who planned to be arrested today if President Bush would not agree to meet with them gathered in tents for a workshop on what to expect from police.

Protest veteran Gordon S. Clark, coordinator for Iraq Pledge of Resistance, a network of antiwar activists, laid out the group's planned route from Foundry United Methodist Church to the White House "picture postcard zone," where he said arrests might occur. Over the weekend, four antiwar protesters were arrested on charges of disorderly conduct.

A representative of the National Lawyers Guild then briefed the audience on the arrest process before fielding questions.

"Our buses are leaving at 7 p.m.," one activist said. "Is there any chance we can get out of jail by then?"

"Don't hold your breath," the lawyer said.

Serving as a backdrop to yesterday's support-the-troops rally was a gigantic flag created by children at Fort Benning, Ga., who decorated 900 red and white squares to reflect what "freedom means to me." At the back of the crowd, participants held a banner that read, "God Bless Our Soldiers Liberating the World One Tyrant at a Time."

Attending the rally were many who said they traveled far to support those they said are protecting the cause of freedom, some at the cost of their own lives.

Antia Grater, 60, and her husband, John, 59, traveled to the rally from their home near Niagara Falls, N.Y. Their son and his wife were stationed in the Persian Gulf country of Qatar until they returned to the United States a year and a half ago. Grater said the military is a family that has to stand strong.

"I believe in what they're doing," Antia Grater said. "A man over there," she said gesturing, "has a sign that says 'Stop the War.' Well, that's what our troops are doing. They're stopping the war on terror at the source."

Roger Custer, 23, of Annandale didn't speak publicly, but he did his best to make a statement, fashioning a cape out an American flag.

"I support our troops," Custer said. "I support our president. I support our mission in Iraq. I'm proud to be out here."

Also expressing pride were the many family members who spoke during the rally about their loved ones, some of whom died while serving in Afghanistan and Iraq.

Debra Argel Bastian lost her son Derek, 28, of Lompoc, Calif., when a plane he was in crashed May 30 outside Baghdad. She explained tearfully that her son believed in his family and his mission.

"My son had a tattoo on his back that read, 'Never forget,' " she told the audience. "All of you please, never forget."

Doug and Charlotte Smette of Makoti, N.D., whose son Keith Smith died during the war in Iraq, listen to speakers at the rally on the Mall.A placard-holding Becky Lepire of Fredericksburg displays her viewpoint, as she and other supporters of military actions face off against antiwar activists across Fourth Street.Sherri Francescon of Camp LeJeune, N.C., records cheers for a tape she intends to send to her husband in Iraq.