McDonald's may have lowered the price of the Big Mac to 55 cents, but that won't affect too many people in Harvard Square, where fast-food chains are about as common as aquatic life in the Charles River.

The Harvard Square Defense Fund has been one of the most effective and pugnacious community groups in Cambridge, fighting to defend the small-town, Mom-and-Pop feel of the Square against what it sees as the encroachment of big-name businesses--the so-called "chain creep."

But hopeful entrepreneurs and real-estate moguls assert that the Defense Fund is a legalistic group of obstructionists whose only achievement has been to stymie free enterprise in the city and usurp what should be the prerogative of consumers.

The 450-member group is adept at winning compromises in development proposals through skillful negotiation--and litigation.

Since 1988, the Fund has filed five lawsuits. In three of those cases, the Fund's tenacity brought results.

* In 1989, the Fund sued Harvard and a developer, Carpenter and Co., after the city Planning Board granted them a permit to convert what is now the Harvard Square Hotel into a six-story office building. Eventually, the University dropped its plans to develop. The developer sued the Defense Fund, but the case was settled out of court, according to Defense Fund President Gladys "Pebble" Gifford.

* In 1992, the Fund sued Harvard, challenging the plans to build Harvard-Radcliffe Hillel's Rosovsky Hall, which required a special permit to provide fewer than the required number of parking spaces. Harvard and the Fund settled out of court, with the University making concessions in the building's height, although that had not been an issue in the lawsuit.

* In 1996, the Fund sued Baldini's, an Italian restaurant chain, contesting the transfer of a special permit allowing the company to open a fast-food restaurant on the Harvard Student Agencies property on Mt. Auburn Street. During the suit, Baldini's dropped its effort, though the Defense Fund maintains the two events were unconnected.

In two other cases the Fund was not so successful.

* In 1989 the Fund lost a major effort to scale down what is now One Brattle Square--home of such shops as HMV Records and Compagnie Internationale Express. In a major defeat for the Fund, the court ruled that it had no legal standing to challenge the project.

* Last year, the Fund's attempt to prevent the opening of a Starbucks on Church Street was thwarted when its suit was dismissed from court.

Detractors say the Defense Fund's tactics are heavy handed--last year it hired a high-school student to photograph people entering and leaving Starbucks Coffee to demonstrate "congestion." But supporters assert aggressive methods are necessary to get results.

Gifford says that "80 percent of the work we do has nothing to do with lawsuits," but tax returns filed by the group with the Massachusetts Attorney General's Office between 1990 and 1995 indicate that 85 percent of the more than $114,000 it raised during that period went to attorneys.

"The Defense Fund plays a necessary watchdog function in the Square," says Charles M. Sullivan, executive director of the Cambridge Historical Commission and a 32-year resident of the city. "It's an area where the stakes are highest and the controversy's the sharpest. And the Defense Fund has been correspondingly vigorous."

Others assert the only result of that vigor has been to leave Square businesses and residents frustrated. "Some people feel that it's a waste of time, energy and money and that the whole process is frivolous," says a board member of the Harvard Square Business Association who asked to remain anonymous.

Losing the Village Feel

Sitting in the Algiers Cafe, sipping a cup of chamomile tea amid the din of conversation, Gifford, 10-year president and a founding member of the Defense Fund, peers over her glasses intently and describes what she thinks is special about the Square.

"There are wonderful shops, and I know the merchants. You feel like you're a member of a community," says Gifford, a real-estate agent. "It sure beats the mall."

"If it doesn't exist in the Square, no one gets it for Christmas," she says, noting that her family moved recently "to enjoy the Square without driving a car." The family eats out frequently, and when the children come home to visit, Chili's on Mt. Auburn Street is a favorite restaurant for dinner.

But Gifford and other members of the Defense Fund see a tendency toward change for the worse in the Square.

They point to development projects such as One Brattle Square, the Charles Square Hotel and the Kennedy School of Government as buildings that "canyonize" the Square, destroying the historic, low-rise character that makes it unique.

In addition, Defense Fund members feel that the Mom-and-Pop establishments which make the Square more than a mall are threatened by national chains that can pay higher rents, edging out their smaller competitors.

"We think what makes the Square special, what people come here for, is the Brattle Theatre, the Tasty, Algiers, Casablanca--for the things that are different," says Gifford.

But not every Harvard Square loyalist carries a Defense Fund membership card.

For 41 years, Alexander M. "Sandy" Cahaly ran a men's clothing store store on Brattle Street. His father had run a grocery store on Mt. Auburn Street, where Christy's now sits.

"I literally grew up in Harvard Square," he says in a characteristically gruff voice.

"I have made my living in Harvard Square. I am one of the people who love Harvard Square and want what's best for the Square."

Legal Tangles

In 1995, Cahaly needed to find a new tenant for his property on Church Street when Steve's Restaurant closed.

Before choosing a tenant, he and his wife, Janet A. Cahaly, came up with a "wish list" of what they wanted their lessee to offer the Square.

"When we ran the clothing store we'd have tourists come in with a youngster bouncing up and down who really had to use the bathroom," he recalls.

So they asked for public restrooms, and a tenant who would hire from within the community, run a clean operation and not detract from other business in the Square.

Starbucks Corp. met the bill, agreeing also to preserve the historic character of the building--the site of Cambridge's first jail.

But before the coffee could brew, Starbucks needed a special permit from the Cambridge Planning Board to operate as a fast-food restaurant.

The Defense Fund argued that Starbucks didn't adequately prove there was a "need" for Starbucks coffee that could justify granting an exception to the city ordinance restricting fast-food establishments.

To prove that point, the Defense Fund took a survey of area restaurants and found that there were already more than 1,000 seats for coffee lovers in the Square. It also hired a student to take photographs as evidence of coffee-shop crowding.

The city's Planning Board gave the go-ahead anyway, and the Fund filed an appeal. But the Defense Fund never got the chance to show its research in court. Starbucks motioned for summary judgment, and the case was dismissed for a lack of standing.

The Fund may appeal the ruling. In the meantime, Cahaly says he's happy with what Starbucks has brought to the community.

"What could be more Harvard Square than what's going on there now?" he asks. "I walk by in the morning and see people reading the newspaper, sipping coffee and working on their laptops."

If the city approves a project that the Defense Fund feels would threaten the Square, the Fund's 24-member board can file a suit in the Superior Court of Middlesex County, naming the developer as well as the members of the Planning Board as defendants.

But Gifford stresses that the group aims for cooperation and views legal measures as a last resort.

"It's not as if we're going around looking for people to sue," she says. "The public sees the appeals, the lawsuits. What they don't see is our participation in the hearings night after night. We don't just come in out of the blue after the decision."

In addition to its legal work, the Defense Fund holds annual meetings designed to educate the public on issues concerning the Square, publishes an annual newsletter, and concerns itself with "street-life" issues within the Square.

Vigilance is the price of maintaining the Square's traditional feel, Gifford says.

"I just don't want to see a Starbucks on every corner of every street," she says.

How It Began

The Defense Fund was born out of a struggle in the mid-1970s to develop the area where the Kennedy School of Government and the Charles Square Hotel now rest.

At that time, the property belonged to the Massachusetts Bay Transportation Authority (MBTA) and was used as a "car barn," where subway cars were parked when not in use.

Priscilla J. McMillan, treasurer and a founding member of the Fund, remembers the conflict as a galvanizing force for local residents who until that time had been divided into sectional neighborhood associations.

"People were beginning to be more environmentally conscious and began to realize several things at once."

Plans for a memorial library and museum dedicated to former President John F. Kennedy '40 would have meant more tourist buses, cars, congestion and pollution.

The residents won a compromise, and Columbia Point in Dorchester was chosen as the final destination for the Kennedy memorial.

The Defense Fund was founded out of that struggle as a non-profit corporation in 1979, dedicated "to preventing the environmental and ecological deterioration of the Harvard Square area."

Whose Job Is It?

At the crux of many disputes over development in the Square is the granting of special permits that allow developers to deviate from the standard zoning requirements.

Special permits, unlike variances, do not require the applicant to demonstrate that a hardship is imposed by the zoning ordinances, says Lester W. Barber, the director of land use and zoning in the city's Community Development Department.

"[The Defense Fund] views the special permit as something that should almost never be given," Barber says. "That is not how the Planning Board...views it."

Members of the Defense Fund argue for a more restrictive approach to special permits.

"Special permits should be specifically for the community and not the developer," says John R. Moot '43, a member of the Defense Fund's board of directors.

Critics of the Defense Fund dispute its interpretation of the law, and some even assert that the group should not be in the business of legal interpretation. One Harvard Square property owner, who spoke on condition of anonymity, said he approved of public debate over development, but only in the "proper forum."

"Part of the thing with the Defense Fund is [it wants to] seem like the 'big monster,'" he said. "It wants people to pay homage to it first" before presenting plans to the Planning Board.

Gifford described citizen involvement with the development process as a "backlash" against years of neglect by the city and as an effort to look out for Cantabrigians' concerns. "If the residents hadn't responded to the total abandonment by the city, it would have been much worse," she said.

A frequent catch phrase offered by proponents of the Defense Fund is, "Don't kill the goose that laid the golden egg."

"The goose is that unique thing that we all feel is Harvard Square," said Moot. "The golden egg is the revenue that it yields to the city."

'Killing the Goose'?

But property owners maintain that they have no interest in destroying the appeal of Harvard Square.

"Think about the logic here: the developers have an interest in killing the goose? The Defense Fund, which doesn't own property in the Square, is actually better qualified?" muses one Harvard Square landowner.

"They want it in their image and likeness. They have a particular omniscience in knowing how many coffee shops should be here," he says, referring to the Defense Fund's challenge to Starbucks.

Other detractors feel that customers, and not residents, should be the final judges of Harvard Square, and that change is the inevitable companion of time.

"Harvard Square is not their private Disneyland," says Janet Cahaly. "It's a commercial area."

Her husband agrees. "The goddamn fools [who opposed Starbucks] are afraid of competition, and in the retail business we used to say, 'If you can't stand the heat in the kitchen, get the hell out," says Sandy Cahaly.

Breaking the Chains

Many have argued the "chain creep" crisis is overstated.

According to Kristen T. Sudholz, executive director of the HSBA, "the Square is still a good niche for Mom-and-Pops to open new businesses."

Figures from a recent HSBA study indicate that of the stores which have closed in the Square during recent years, only roughly half were "Mom-and-Pops," the other half chain stores.

And in an odd way, unique stores can find their way to national-chain stardom by starting in the Square, say some, pointing to Pier One Imports, Learningsmith, Au Bon Pain, Cybersmith and Newbury Comics as stores--now chains--that got their start in the Square.

Developers, city officials and Defense Fund members alike insist they're striving to reach a balance of interests in Harvard Square.

And though the Defense Fund logo--a map-like street grid with an arrow shooting upward--may imply a single direction for Harvard Square, local business people and residents will doubtless continue to be divided in their support for the group.

Developers assert the Fund's grass-roots tactics, while noisily aggressive, serve only to cripple the evolution of the Square. The board member of the HSBA asks: "The Defense Fund can rally people--they can do that well--but at what benefit?"

But long-time residents say that the character of the Square is irrevocably disappearing.

"They really used to roll up the sidewalks at 8 p.m.," Sullivan recalls. "In the middle of the 1960s, Harvard Square was really a college town. Stores served homeowners, housewives and college students."

Gradually, that homely atmosphere has faded away, Sullivan says.CrimsonGrigory Tovbis"Harvard Square is not their private Disneyland," says JANET CAHALY, who, with her husband ALEXANDER, fought off a Defense Fund suit.