A summer trip to the U.S. for a total-immersion dunk in the English language -- a rite that usually sends hundreds of thousands of foreign students chattering around the country -- has lost much of its cachet this year.

"My father told me to choose between two countries, the United Kingdom and Canada," says Firas Al-Hoshan. "When I asked him about the United States, he told me: 'Don't go.' "

Mr. Al-Hoshan picked Canada. The 22-year-old from Saudi Arabia is taking his English plunge in Nova Scotia. So many other foreign students are making similar choices that intensive-English enrollments have thinned by a third since 2001, accredited U.S. schools report, and academic-year courses are down 20% since 2002.

The full impact may be even greater. In 2001, 150,000 enrolled in all summer English-language courses in the U.S., estimates William Fish of the Washington International Education Council, an advisory service; this year, only 90,000 foreign students may have come.

In many of these cases, students are avoiding the U.S. due to the arduous process of getting a visa. The tougher visa requirements that have come into force since Sept. 11, 2001, may be keeping some phony students at bay, but they may also be a threat to the business of educating genuine foreign students in the U.S. -- a $13 billion-a-year industry that goes far beyond summer language lessons.

America's colleges and universities view English proficiency as an essential skill for future full-time students, and the summer English courses have been a main route into U.S. lecture halls for foreign students. The effect of the declining language-school enrollment on the broader foreign-student population -- nearly 600,000 at last count -- won't be known for months, but any decline could be costly for U.S. colleges. Because foreign students usually pay full tuition, they offset the support given to Americans who have come to expect financial aid.

The new U.S. visa rules, which involve security checks and entry of student details into a new computer network, will get tougher Aug. 1, when more applicants will be subject to interviews. Some consular officers already mistrust language students. Intensive-English courses are short. Ability to pay -- mostly under $5,000 -- is the one requirement. Though statistics aren't public, some schools not screened by the two national accrediting bodies could be visa mills, or so officials suspect.

Yet the more than 300 certified language schools are hurting, too, and not solely because of students denied visas.

Fati Erdogan, who markets the intensive-English program affiliated with the University of Southern California at Santa Barbara, says recruiters from other English-speaking countries discourage applicants from choosing the U.S. Her 2001 students came from 48 countries; more like 20 sent this year's crop. Turks and Saudi Arabians have dwindled. So have Czechs, Poles and Brazilians. The Japanese, for years a bulwark of the business, are wandering away in droves.

"They feel the U.S. is not a safe place," says Hiroto Shindo, a consultant who helps students find schools outside Japan. "When 9/11 happened, it reminded them of that. English students don't have to be in the U.S. They can go to Canada, U.K., Australia."

"We're out to take market share away from the U.S.," says Richard Law, who promotes the mother tongue at the state-supported British Council in London. A recent e-mail to schools and recruiters from Canada's equivalent, the Education Center Network, predicted that a "growing suspicion" toward foreign students in the U.S. would "discourage many applicants" and benefit "more welcoming" countries that "adapt their marketing strategies to take advantage."

Australia, New Zealand, Ireland -- even Malta -- are more welcoming than ever to intensive-English consumers. Britain recovered from a 2001 dip -- attributed partly to terror, partly to foot-and-mouth disease -- and pulled 2002 enrollments up 20%, to one million student-weeks a year.

For instruction of any kind and any length -- whether ski lessons or flight training -- the U.S. has long required student visas. Now, just as America's security regime has made these visas harder to get, Britain, Australia and New Zealand have dispensed with them for courses under six months. Canada did the same a year ago.

As has been the case in the U.S., these countries' objective is to steer students who come to learn the language into lucrative full-time study. The Australian government's latest budget sets aside US$75 million to promote such education for foreigners. In 2000, Britain hired an ad agency to create a "brand" image and launched a campaign to bring in 75,000 more students from beyond the European Union by 2005.

The U.S. government has never had to run promotions. Foreign students, hoping for degrees and jobs here, accepted no substitutes for American English. Today, studying the language's rival "brands" is coming to hold the same appeal, without all the complications.

Why did Firas Al-Hoshan choose Canada? "It's similar English to the United States, that's why," says the young Saudi, who is learning the language at Halifax's International Language Institute, which shares a shopping center with a bowling alley.

Mr. Al-Hoshan will enter nearby Dalhousie University after buffing his English. A fellow student, 23-year-old Saud Al-Khoory from the United Arab Emirates, is headed for the University College of Cape Bretton.

"I'm going home to renew my visa and come back," he says. "It won't be a problem. It's easy to get a Canadian visa." How much easier than getting a U.S. visa? The two classmates aren't sure. Neither took the trouble to apply.