HORDES OF unidentified foul objects are diving into France's plates. Quick, let's all grab our pots and pans and chase the enemy away!"

Thus began a horrified commentary by gastronomic gurus Gault et Millau in their monthly wine and food magazine, lamenting the uncontrollable invasion of fast-food shops in the land of Paul Bocuse, coq au vin, creamy bries and beaujolais.

Long ago, America invaded French closets with Yankee jeans and assaulted Gallic ears with rock 'n' roll. But until recent years, their stomachs were strictly off limits. Hamburgers? Quelle horreur!

Paris has long resisted the onslaught of the barbarian burgers, though there were those like Jacques Borel in the late 1950s tried to launch an attack by introducing "ze fast-food" with a Wimp in the heart of Paris' Latin Quarter.

In 1972, however, McDonald's managed to run the blockade, and within a few months, the capital of gastronomy surrendered to the invaders. The beef patty had finally succeeded in conquering some Frenchmens' palates.

McDonald's founding father, Ray Kroc, awarded the pilot franchises in Paris and its suburbs to Raymond Dayan, a 48-year-old French businessman who somehow managed to get the finicky French to swallow 36 million burgers within three years.

But last year, the Franco-American liaison soured, and Kroc's Chicago-based burger empire filed suit against Dayan's establishments, claiming that the French McDonald's did not meet American standards. The case is still pending.

Dayan thinks, however, that the real reason behind the court case has less to do with maintaining company standards than it does with the original terms of the franchise agreement, which entitles the Chicago office to only 1 percent of Paris profits compared to the usual 11.5 percent. "I don't think they thought it [the Paris franchise] would work back in 1972," commented one member of the industry.

Today there are almost 200 different fast-food outlets in France, and industry specialists expect a fivefold increase by 1990. According to a recent nationwide survey, one out of three Parisians last year confessed to having tasted the alien burger.

But France, where the fast-food industry accounts for a mere 0.2 percent of the overall restaurant business, is only a minor target of the fast-food invasion thus far. Its neighbors have been a little harder hit: Fast-food enterprises make up 2.7 percent of the restaurant business in West Germany and 3.3 percent in Great Britain.

Although McDonald's and Burger King have fought their respective ways to to the top of the burger wars, these American giants aren't the only games in Paris. French copycats with American sounding-names such as Pop Inn, What A Burger, Chicken Soup, Hit Burger, Quick and . . .Love Burger are fast becoming part of France's culinary vocabulary.

Strolling down the Champs-Elyse'es these days means passing no less than six fast-food shops cheek-to-jowl with Dior perfumes or Gucci shoes. And perhaps inevitably, that mecca of sin called the Rue Saint-Denis now offers a new and exciting divertissement for wary travelers: "The Love Burger." Located just above a gaudy sex shop, the eatery attracts up to 1,800 customers day and night, with peak hours being after midnight.

Indeed, the fast-food industry in France is becoming so prosperous that last year alone overall revenue totaled tens of millions of dollars. And an expected 30 percent profit margin--compared to a nightclub's 25 percent or a grocery store's 15 percent -- makes the business all the more attractive to small private investors clamoring for franchises.

Few investors are capable of meeting the industry's strict requirements: quality service, cleanliness -- but those who do are becoming serious competitors for all-American Burger Kings and McDonald's.

Take a place on the Champs-Elyse'es called Free Time, for example, which prides itself on being "all French." Homesick Americans stay away! And don't let the names fool you. The "hitburgers" and "funburgers" are actually tender spiced steaks served on crispy rolls. Overruling the fundamentals of American fast-foods operations--which call for non-alcoholic beverages--Free Time, like all its other counterparts in France, serves beer.

Why beer in the home of some of the world's finest vineyards? "Wine is un-American," explained one fast-food owner.

"What we are after," a Free Time spokesperson said, "is the French taste: better-tasting meat, homemade French bread, local smoked ham."

So why the camouflage? "The hamburger is an American product. All those fast-food nuts who long for America are attracted to the burger," said Guy Raoul Dharambure, head of the French firm that owns Free Time.

But the idea of an eat-and-run restaurant has become so popular that some French entrepreneurs have decided to drop the burgers and American-style facade in favor of creating fast food around one of their own specialites--croissants.

In order to attract gastronomic purists, French fast-food think tanks introduced "the croissanteries" in 1976--sort of a McDonaldization of the French pastry staples: flaky croissants and soft brioches.

Today, more than half of Paris' 88 fast-food shops are "croissanteries." The concept has proved so successful that shops have opened from London's Strand to New York's 57th Street and Washington's K Street. The game's the same, though in Washington it's Croissant Chaud, while it Paris it is Croissant Show.

Despite all these advances, the incredible boom in the fast-food industry had somehow gone by practically unnoticed until early April, when a three-day fast-food fair, inaugurated by consumer minister Catherine Lalumiere, opened its doors to an appalled but curious public.

The minister's presence at the fair, said some observers, seemed to fall in line with the socialist government's desire to promote popular eateries at the expense of four-star retaurants. Indeed, last winter, the government adopted a series of tax measures aimed atincreasing the amount of taxes paid by the rich. One measure included in the socialist wealth-tax menu was a 30 percent tax levy on business spending, which ultimately meant a drastic cut in expense-account travel and dining.

But for French culinary chauvinists the fast-food fair was considered a direct violation of the sanctity of French food. How could a Frenchman decently look at another boeuf bourgignon with a clear conscience? French tastebuds had been insulted.

The exhibitors offered legal and financial advice for potential investors and free samples of various burgers, and they previewed new ideas for the fast-food industry. The latest: "the fast food station," a mobile trailer shop.

French media gave the event ample coverage, with page-one headlines proclaiming "Everything You've Always Been Afraid to Ask About Fast Food" and "The Invasion of Fast Grub: Yukky or Yummy?"

According to the Association de la Restauration Rapide (Fast-Food Association) established just a year ago, fundamental changes in Frenchmens' eating habits partly explain the sudden popularity of the fast-food factories.

Open until after midnight, the stands serve everyone from secretaries who can't afford gastronomical luncheons to rushed workaholic executives. A $4 meal--including a hamburger, large orders of french fries and a large cola--is a lunch bargain on the Champs-Elyse'es where normally $10 buys a mug of beer and half a sandwich.

Quick service (an average of three minutes from order to bagged lunch) is also appealing to Parisians used to overcrowded brasseries and constant bickering with waiters. Although currently only 15 percent of the shops' customers are over 30, the industry has launched a substantial nationwide advertising campaign in an effort to lure an additional 25 percent of older diners to their doors by 1990.

Has junk food finally succeeded in conquering the land of haute cuisine? Will Lasserre be deserted? Taillevent abandoned? Bocuse forgotten? Troigros ruined? "Jamais de la vie!" say the culinary diehards. But if the fast-food entrepreneurs have their way, Frenchmen will be "deserving a break today," along with all their counterparts this side of the Atlantic, for a long time to come.