In numbers that haven't been seen since the Vietnam War, US citizens of many backgrounds have been moved to demonstrate their opinions and feelings about the war in Iraq. We recently asked people from both camps to tell us what has motivated them.

FAVORING THE WAR

Annabelle Guerra, 19, student, part-time worker at the Environmental Protection Agency, Roslindale

The most important factor in your decision? "After so many years of attempting to have a peaceful relationship between us and Iraq, I feel for the safety not only of the US but for the Iraqi people. Something had to be done."

The other side's most persuasive point? "No one wants war."

Why demonstrate? "It's not even for the government; it's for the people. The citizens here and overseas need to see who the Americans are really supporting."

The closest person affected by the war? "I have two friends, more than anything they're family friends, who are in the service."

The last cause that moved you to demonstrate? "I demonstrated strongly when the Clinton administration and Janet Reno took Elian Gonzalez away from his family in Miami."

Greg Margolin, 45, computer engineer, Brighton

The most important factor in your decision? "Iraq is the major logistic base for terrorism and the terror war against America."

The other side's most persuasive point? "The president needs to make a better case for war."

Why demonstrate? "It's the same point as voting and making your opinion known. We live in a democracy. You have a chance to influence other people; you have a chance to influence your elected officials. That's how it works."

The closest person affected by the war? "My best friend, Israeli photo artist Nathan Brusovani, in Jerusalem. Saddam is moving his missiles to be of danger to Israel, so they're in danger, and they'll be in more danger."

The last cause that moved you to demonstrate? "I went to Washington as a part of the Jewish Russian Center for a rally in support of Israel a couple of months ago."

Bill Wilkins, 57, engineer, Haverhill

The most important factor in your decision? "President Bush and Secretary Powell presented a good case that not only is Mr. Hussein persecuting his own people, he's a danger to the world."

The other side's most persuasive point? "I don't think they have any at all. It's a replay of the '60s, where they found a nice little repressive regime, and for no other reason than that [Saddam Hussein] is against the US and President Bush, they're for him."

Why demonstrate? "We're more or less out there supporting the troops. I'm a Vietnam veteran. I don't think there was much overt support for us in the '60s, so a bunch of us decided to go out and reverse that."

The closest person affected by the war? "Our clerk at work. Her husband is in an engineering batallion, and he's on his way to Kuwait."

The last cause that moved you to demonstrate? "I was out [supporting Bush] for the president back in 2000."

Aaron Goldstein, 30, unemployed, Boston

The most important factor in your decision? "Any country that has weapons of mass destruction or is intent on building them, that is a situation that the world cannot afford to tolerate."

The other side's most persuasive point? "I really haven't heard one on the other side. Most have been centered around how bad a person George W. Bush is."

Why demonstrate? "I think it's important, as an American and living in a participatory democracy. You have to participate."

The closest person affected by the war? "I don't know if there's anyone in my immediate family that would be affected. There's the question that retribution might take place, and I have family in New York; that's always a potential effect. I'm personally more worried about a potential conflict with North Korea because my sister lives in Seoul."

The last cause that moved you to demonstrate? "Before Bush went to the UN in September, I'd been speaking out for Israel and other Jewish causes."

OPPOSING THE WAR

Alice Copeland Brown, 65, software engineer, Canton

The most important factor in your decision? "My son [an Army major in Kuwait] . . . has been put into harm's way by an unconstitutionally seated president, acting unconstitutionally to declare war."

The other side's most persuasive point? "OK, Saddam Hussein is a pretty bad guy. That's about as close as I can get."

Why demonstrate? "I believe there are millions of Americans who really constitute a moral majority. And if they are encouraged by the sight and sounds of us, then this invasion may be stopped."

The closest person affected by the war? "My oldest son, Major David E. Floyd."

The last cause that moved you to demonstrate? "The theft of the presidency in 2000."

Vernon Domingo, 52, geography professor, Bridgewater

The most important factor in your decision? "No direct link has been made between Saddam Hussein and Al Qaeda."

The other side's most persuasive point? "He does oppress his people. He's caused enormous pain to his own people and to the Kurds as well."

Why demonstrate? "Voices opposing this must be heard. This has been important throughout history."

The closest person affected by the war? "Some of my students . . . have been called up."

The last cause that moved you to demonstrate? "The big one. I'm from South Africa; I'm a black South African, and there the issue of apartheid was something I felt strongly about."

Anna Falicov, 22, student, Cambridge

The most important factor in your decision? "There has been absolutely no case that's been made for this war that's convincing."

The other side's most persuasive point? "It hasn't been proven to my eyes that Saddam Hussein is a threat, and even if he were, I don't think that calls for preemptive war on the Iraqi people."

Why demonstrate? "I think it's very disturbing to have a president not respond to what is the majority of the will of his constituents. That's not democracy."

The closest person affected by the war? "I do have a classmate who was deployed last month."

The last cause that moved you to demonstrate? "The living-wage campaign here at Harvard."

Alice Rothchild, 54, obstetrician/gynecologist, Brookline

The most important factor in your decision? I think that the war will be catastrophic in terms of what's going to happen to the Iraqi people and what's going to happen to the US in the global community and in our economy at home."

The other side's most persuasive point? "That Saddam is a despot."

Why demonstrate? "I think it's very important in a democracy to make your voice heard, and if there's going to be a solution, even if we go to war, the antiwar voice is going to be important."

The closest person affected by the war? "My daughters. The one that's in high school is going to have the consequences of a war economy. . . . My daughter in college, this is her struggle. . . . It's almost her Vietnam."

The last cause that moved you to demonstrate? "Vigils for Palestinians, calling attention to . . . the occupied territories and the conduct of the Israeli army."