CAN IT BE true that the three-week Baltimore International Theater Festival starting next Saturday will be the first international theater festival staged in the United States.?

In Baltimore?

"At least," says Hope Quackenbush, masterplotting the whole thing, "I now know why there's never been one before. The work has been mind-boggling. We've not located any records of such and we've searched. Besides, we're being careful to call this "the first of its kind' and that's certainly a fact."

Of its kind means 66 performances of nine international attractions ranging from London's National Theatre, Dublin's Abbey Theater, Tel Aviv's Habimah National Theater to groups from Canada, Spain, France, South Africa, Japan and, representing the United States, Louisville's Actors Theater, plus daily attractions for children.

True, at one time or another, the great foreign companies have toured America. There have been international festivals of mime in LaCrosse, Wis., San Francisco and Washington; and, under a "festival" format, foreign companies have moved successively onto a single stage over a period of months.

But all this, within three weeks and running concurrently, does indeed amount to a first. Baltimore is celebrating its highly visible new look, its downtown center, its harbor and its coming subway. It hopes to become an annual.

Quackenbush, managing director of Baltimore's Center for the Performing Arts and the Morris Mechanic Theater, is the festival's executive producer, but she gives credit for the idea to to Al Kraizer, who for several years produced a more modest international Baltimore festival of avant-garde theater which had some civic support but, not suprisingly, failed to electrify the masses or, for that matter, the intellectuals who complain about a lack of avant-garde and are conspicuously absent when it exists.

Perceiving his scheme's limitations, short, dark, mustachioed producing director Kraizer two years ago began thinking Big. His conception and digging to make contacts are the roots of the ambitious scheme.

Quackenbush has been the gardener from her post at the Morris Mechanic, where she's been strikingly successful since she opened the reconstructed Hopkins Place house in 1976. She's built up 18,577 seasonal subscribers for three-week runs and already more than 15,000 of them have resubscribed for next season, a figure no Washington theater subscription plan can match.

Last year came the breakthrough Kraizer's plan needed. Visiting with his celebrated "The Gospel According to St. Mark" reading. British star Alec McCowen fell under the spell of ebullient Quackenbush, from whose elegant apartment overlooking Baltimore's Mount Vernon Square he was exposed to the city's unique charm.

"You know," says Quackenbush, "Baltimore's a rare city, the leisurely, human scale of its past with the lively beat and look of the present. Mayor [William Donald] Schaefer has boosted the downtown area through the Baltimore Center here on Hopkins Plaza, and made possible the transfer of the Center Stage into the former St. Ignatius Jesuit high school. He's completely revived the historic old harbor, once the country's biggest port. And the subway is well along.

"All of these festival events are within walking distance of each other. Along Charles Street, St. Paul Street and downtown have sprung up those fine restaurants and shops which seem to come in once theaters attract the crowds. Having lived for periods of time in a half-dozen cities, I know this to be an unusually pleasing one and was able to convey that idea to Alec."

Al Kraiger had made contact with the British National Theater, "but nothing was set until McCowen decided he loved our town," says Quackenbush. He pushed the idea that the National send its new production of Terence Rattigan's double bill. "The Browning Version" and "Harlequinade" with himself, Geraldine McEwan and Nicky Henson, which will be performed June 11-20.

"That's the way it often is with bookings," Quackenbush notes. "Groups are reluctant to take a lead until a major one does. Then so much falls into place. No, the National will not play anywhere else in this country on this trip.

"How are we affording all this? Well, it just happens that World Airways is instituting a Baltimore-London service and to kick it off its flying the National Theatre company here.

"We're budgeted quite tightly at $850,000 for the three weeks and gurantors have been generous to see the possibilities. If we can get 60 percent capacity on everything we'll just balance the books. It would be nice, though, to do better, so we can firm up next spring's planning. We do want to be an annual, but it must do well the first year to deserve a future.

"Everyone has pitched in. Center Stage is hosting Louisville's Actors Theater in 'Extremities,' the play that was most admired in its Festival of New American Plays this winter." William Mastrosimone's excoriating drama is about a woman's revenge on her molester.

"Center Stage also will be the setting for the multiracial Baxter Theater of Capetown, South Africa. Its production of Samuel Beckett's 'Waiting for Godot' stars John Kani and Winston Ntshona, whose appearances in 'Sizwe Banzi Is Dead' and "The Island" won them a Tony a few years ago."

The booking of a South African theater caused some turmoil when it was announced: The Henry McNeil Turner Society and lawyer Anthony Robinson threatened to mount a counter-festival. Says Quackenbush: a"I truly believe that the objections to the Baxter were raised before there was a thorough understanding in the community of the remarkable nature of this company. And now, with the understanding that the Baxter -- and John Kani and Winston Ntshona -- are courageous leaders in the trenches, if you will, for more freedoms in South Africa, we expect Baltimore to welcome them with open arms."

The Baltimore School for the Arts will be host to the festival's opening attraction, the Habimah National Theater of Israel, playing "A Simple Tale" by Nobel Prize winner Shai Agnon. It's the company's first appearance in this country in 25 years.

Dublin's Abbey, performing in the Mechanic, will be acting the Abbey's centenary production, Sean O'Casey's "The Shadow of a Gunman," staged by Thomas MacAnna June 22-27.

Quackenbush observes: "In our country, which gets less interested in learning foreign languages, English-speaking groups naturally get the most attention. Here is where mime becomes vital to any international theater in the United States.

"From Tokyo will come Mamako Yoneyama, whose studies of Martha Graham and Marcel Marceau have enabled her to open the confines of zen and kabuki to Western breezes. Two groups from Barcelona, Els Jogler and La Claca, and London's Moving Picture Mime Show also will be appearing at the Baltimore School for the Arts.

"The Inner Harbor, just a short walk from Hopkins Place, will be the site for the Festival's Young People's Program. We'll be having an enormous tent along the harbor's edge, which will be home to the Big Apple Circus of New York, featuring that French aerialist, Philippe Petit, who walked across that wire stretched between the twin towers of the World Trade Center.

"Besides mimes, we'll have storytellers, clowns and acrobats performing at the Maryland Science Center, in the streets and restaurants. The Lord Baltimore's cafe will be a meeting place for performers. Everything going on will be within 20 minutes' walking distance.

"Don't press me too much about the logistics of all this, getting the artists through immigration and customs -- and the Internal Revenue Service -- people, their customers, trunks, settings and props. That's under the direction of Richard W. Kidwell, our general manager and, for most of its life, manager of the Kennedy Center Opera House.

"That's the most intricate job we have and the Kidwells -- his wife, Danny, works with him -- won't really get any sleep until the companies for our last days, the 27 and 28th, take off for Tokyo, Dublin, London, Louisville and New York. It's a marvel, all the detail Kidwell and his staff have been handling.

"For instance, do you know what the English call our "three-sheets,' those big signs pasted onto theater boards into three sections? They're called 'Double Crowns," just one of the endless new terms we've been picking up along the way. Did I say that we Americans have trouble learning foreign languages? Even English can be a foreign language when you're involved in an International Theater Festival."