SAN FRANCISCO -- As a Marine in Vietnam, Stan Long served twice the normal 13-month tour in order to help younger, less experienced men avoid the perils of booby-trapped jungles.

After coming home to San Francisco, he became security director of a large hotel on Market Street, voted for George Bush and did not discourage his son, Michael, from beginning a military career five years ago. Michael now is a Marine lieutenant in the Middle East.

This week, however, Long is in the midst of a national effort, particularly intense in cities such as San Francisco and Boston, to keep as many young men and women as possible out of the armed services as the nation faces war.

With several dozen other veterans here, Long, 41, has created a network of telephone contacts, leafleting demonstrations and public speeches that have multiplied the number of conscientious-objector applications.

Several of the most outspoken officers and enlisted men trying to avoid duty in the Persian Gulf have received publicity, but the growing network of veterans encouraging their actions still operates largely out of the public eye. Many of its members are juggling career and family responsibilities in trying to bring hope to young people desperate about the possibility that they might have to kill Iraqis.

"If I had realized that Bush's thousand points of light were going to be tracer bullets pointed at the nation's youth, I wouldn't have voted for him," Long said during lunch at a Vietnamese restaurant near Market Street.

"This group is totally run on pain," said Peggy Tuxen-Akers, 43, who served in Vietnam as a nurse. "We have all seen the pain of war, and we don't want it to happen again."

Their organization, United Bay Area Veterans Against War in the Middle East, was created at an evening meeting three weeks after Iraq invaded Kuwait. One Vietnam veteran, Paul Cox, 42, a civil engineer, said he considered the gathering "just a chance to talk about our emotional problems" as another war approached. But the 15 people from different veterans groups quickly agreed to a new organization with specific goals.

Long outlined the principal slogans: "1. No blood for oil, 2. Support G.I. resistance, and 3. Bring the troops home now."

Initially, Long said, he did not like slogan no. 2. "My thought was of a guy in the middle of battle who throws his weapon down and says, 'I'm not going to do it any more,' which is only going to get him and a couple of his buddies killed." He was persuaded that the focus instead would be on helping conscientious objectors to leave the service long before facing battle. {Related story, Page B7.}

Karen Jewett, a staff member with the San Francisco office of the Central Committee for Conscientious Objectors (CCC0), said a surge of calls has come into its tiny four-room office near Union Square. "We're probably getting about 100 calls a day," compared with 15 to 20 a day before the invasion Aug. 2, she said.

About 80 percent are from military-age men and their parents asking about the prospects of a draft and how to avoid service, and the remaining 20 percent come from active-duty personnel.

Several area veterans are serving as counselors for soldiers who want to apply for conscientious-objector status. Since the invasion, the CCCO has trained 300 more counselors.

Keith Mather, famous in antiwar circles as a leader of the "Presidio 27" uprising of San Francisco-based soldiers in 1968, has been a counselor for years and has handled a new flood of calls and speaking invitations. Mather spent several years in Canada after escaping from the stockade at the Presidio army base here. Although he eventually won a discharge with little time in prison, he is frank with callers about the risks of openly defying military orders.

"There are no guarantees in life," he said. "But I do bring up my belief that there are moral laws that are higher than others."

Nearly 100 veterans are involved in the San Francisco organization. Its office is a desk and a file drawer, with a telephone and an answering machine inside the drawer.

The veterans' range of opinions and backgrounds also has caused trouble on the left. Long said he was barred from the platform of a Berkeley antiwar teach-in because the hotel where he works is in a dispute with a labor union.

The incident did not seem to bother the veterans. "We support the military," Long said, "the warriors, the soldiers, the grunts."

Joel Preston Smith, 29, an army photojournalist at the Presidio who has filed for conscientious-objector status, said, "Veterans have a unique credibility with soldiers. They are compatriots of a sort."

Beverly Marino, whose 20-year-old son is in the brig at the Marine base in Camp Pendleton, Calif., for refusing to train, said, "We really need to let these kids know the options available to them."

United Bay Area Veterans' leaflet lists a series of weekly demonstrations and the telephone numbers of several antiwar groups. The CCCO number is listed in bold-faced capital letters, as are the numbers for the White House and Capitol switchboards.

CCCO attempts to send its message even farther by giving the military address established for well-wishers seeking to correspond in general with Americans serving in the Persian Gulf.

"Write to a soldier in Saudi Arabia telling her or him that you are working for peace and a diplomatic, nonviolent solution to the crisis," it says.

Long said he often has thought recently of the day when his son asked for help in persuading his mother, to whom Long was not married, to let him enlist in the Marine Corps. How does the mother feel now? "She's mad as hell," Long said.