"It's like trying to squeeze Jello-O," Martha V. Pennino, vice chairman of the Fairfax County Board of Supervisors, said of the continuing fence fight between the county and the CIA.

At issue is a chain link, barbed wire fence at the Reston Corporate Center, an office complex where the CIA is an occupant. The county wants the fence dismantled; the CIA says the fence is needed, partly to establish a secure "site perimeter zone of control."

The concept of site perimeter zones of control is alien to Reston, which prides itself on being a model "open" community.

"I guess that's probably what the concern is," said Sharon Foster, a CIA spokeswoman.

Chain link doesn't sit well with Restonians, either. The community's design guidelines specify that even doghouses may need landscaping, to "soften" their appearance.

The CIA assured Fairfax officials in November that the fence around its offices was "temporary" until an "alternative site access control system" is developed. But the officials, fearing that "temporary" might stretch into "permanent," are pressing again for a resolution.

"They don't have a right to leave it up for perpetuity," said Pennino, who once described the fence as Lorton Reformatory-like. Pennino, in whose Centreville District the offending structure rises, said the county will keep trying "friendly persuasion." If that doesn't work? "We'll harass them," she said.

"They've got this sense of 'We're in charge . . . . We're bigger than you . . . . We're the federal establishment,' " she added.

Denton Kent, deputy county executive for planning and development, said he finds the entire fence issue confusing.

"Probably 'veiled' would be a good word," he added.

It's not unlike the circumstances surrounding a $100 million addition to the CIA's Langley headquarters, 10 miles to the east, that Foster said is nearly complete. Local officials joked that the only way they could see the site would be to fly over it in a helicopter.

Langley is a "federal enclave," so no local permits are required, the officials said. "We don't have any information on whether that's started, or under way, or what it is," Kent said of the addition.

County officials seem only slightly more clued in about the CIA's presence in Reston.

"We do know that the fence is still there," Kent offered. Do Fairfax officials have the power to order it dismantled? "There's a real question whether we do or not," he said.

Neither Kent nor other Fairfax officials appeared to know what the CIA is doing in Reston, and the agency isn't volunteering anything.

"We don't discuss what we do at any of our facilities," said Foster.

The fence was constructed about 18 months ago by the Reston project's owner-developers, Mulligan-Griffin & Associates of Rockville, county officials said. The developers said they would take the fence down when work stopped.

Fairfax officials think -- but are not certain -- that it has, at least temporarily. They think -- but are not positive -- that the CIA is now the project manager.

"I don't know if I mean 'management of the whole project' or not," said Kent. "It's cloudy."

An official with the development company could not be reached for comment.

The CIA informed the county in writing last fall that its fence "must" remain until a permanent alternative is designed -- possibly within six months. Any plans for a permanent structure would be submitted for public review and comment, the agency said.

"Please be assured that we are fully aware of the concern of the Reston Home Owners Association, and that we are anxious to resolve this issue to our mutual satisfaction," wrote William F. Donnelly, deputy CIA director for administration.

"I'm still trusting that they'll live up to their word," said Joseph Stowers, cochairman of the Reston Community Association's planning and zoning committee.

"I think I'm more annoyed than frustrated," said Pennino.