The federal Alcohol, Drug Abuse and Mental Health Administration staged a giant pep rally yesterday for the Persian Gulf troops, a two-hour festival complete with live rock music, a desert mural and a booth inviting bureaucrats to tell a joke.

To some employees, the rally at the agency's Rockville headquarters was a chance to mingle with unfamiliar co-workers and to contribute toothpaste, perfume and tinned food to U.S. forces fighting a distant war.

But others said the Valentine's Day "Benefit for Our Troops" was an attempt to coerce patriotism from federal workers in a carnival-like atmosphere inappropriate for wartime.

"This takes something that is deadly serious and treats it in a frivolous fashion," said Thomas Plout, a senior administrator, as he glanced at the yellow ribbons and bright banners festooning the agency's cavernous cafeteria. "The flag-waving, that's what bothers me," Plout said.

Plout, a 25-year veteran of the agency, said he had complained to a top administrator about the event before showing up along with about 600 other federal employees.

Others refused to attend.

By giving 2 1/2 hours off to the work force of an entire government agency, officials were "using federal funds to advance a political cause," said one grants project officer who stayed in her office during the rally.

"I feel like we are being forced," said the officer, who spoke on the condition of anonymity. "I'm not into killing people. We are being pushed to show up -- no matter what we think of this war."

During the last week, administrators at the agency dispatched repeated invitations and reminders of the rally to its 2,000 employees.

A memo on the rally, circulated this week to all "executive officers" by the agency's deputy administrator, urged "As many of your staff as humanly possible, IF NOT ALL OF THEM, {to} attend and contribute to its success."

Yesterday, large yellow paper ribbons were fastened next to many of the building's elevators. "Attention all hands," the streamers said. "Be there at 2 p.m." The agency also supplied shuttle buses for employees in satellite offices in Baltimore and Bethesda.

Robert Trachtenberg, the agency's deputy administrator, said yesterday the campaign to promote the rally had been "overzealous, no question about it."

"We wanted to sell it in a sense of getting people to come," said Trachtenberg, who noted that the agency's work force was unaccustomed to such a large social event. "I'm very insecure. I didn't want to have a party that no one shows up at," he said.

The rally was the first big undertaking of the agency's morale committee. The committee's original idea was a rally for charity, in which workers would bring clothing and food for local homeless shelters.

But last week, committee members decided it was somehow more fitting to help the U.S. troops and their families. To gain admission, workers had to bring a donation. The morale committee furnished a long suggestion list of necessities and luxuries for waging a desert war: Kool Aid, beef jerky, crossword puzzles, paint-by-numbers kits, nail clippers, sunscreen, sand flea powder and the like.

Marjorie Cashion, an executive secretary in the Offfice for Treatment Improvement, said she had run out at lunchtime to buy cans of tuna fish and tiny boxes of raisins.

"When I learned this was for the troops, then it provided the incentive for me to come," Cashion said. "It is more than patriotism. It is a feeling, we aren't there. It gives us a way of feeling like we are supporting them and doing something for them."

But Bernard Arons, a psychiatrist who has worked there for 11 years, remained in his office. "I think the Persian Gulf War is a very complex issue," Arons said. "Within myself, I find I have very mixed feelings, but all of them are solemn concerns."