ORONTO, Dec. 1 — Canadians and Americans still dress alike, talk alike, like the same books, television shows and movies, and trade more goods and services than ever before. But from gay marriage to drug use to church attendance, a chasm has opened up on social issues that go to the heart of fundamental values.

A more distinctive Canadian identity — one far more in line with European sensibilities — is emerging and generating new frictions with the United States.

"Being attached to America these days is like being in a pen with a wounded bull," Rick Mercer, Canada's leading political satirist, said at a recent show in Toronto. "Between the pot smoking and the gay marriage, quite frankly it's a wonder there is not a giant deck of cards out there with all our faces on it."

Mr. Mercer acknowledged in an interview that he was overstating the case for laughs — two Canadian provinces have legalized gay marriage, and Ottawa has moved to decriminalize use of small amounts of marijuana. But in the view of many experts the two countries are heading in different directions, at least for the time being.

Recent disagreements over trade, drugs and the war in Iraq, where Canada has refused to send troops, has made the relationship more contentious and Canadians increasingly outspoken about the things that separate them from their American neighbors.

"The two countries are sounding more different — after 9/11, dramatically more different," noted Gil Troy, an American historian who teaches at McGill University in Montreal. "You hear a lot more static and you see more brittleness."

Of course there have been frictions before, for instance during the Vietnam War, when Prime Minister Pierre Trudeau welcomed American draft evaders, but the differences in those years were more political than social. Analysts say that Canada and the United States have always been similar yet different, and that the differences are often accentuated at the margins.

But today, many analysts and ordinary Canadians said in interviews around the country, the differences appear to have moved center stage, particularly in social and cultural values.

The nations remain like-minded in pockets, but the center of gravity in each has changed. French-speaking Quebec, with nearly a quarter of the population and its open social attitudes, pulls Canada to the left, just as the South and Bible Belt increasingly pull the United States in the opposite direction, particularly on issues like abortion, gay marriage and capital punishment.

None of those have resonated much over the last decade in Canada, where the consensus on social policy seems more solidly formed, its fissures narrower and less exploitable.

Chris Ragan, a McGill University economist, observed: "You can be a social conservative in the U.S. without being a wacko. Not in Canada."

Drugs are one point of departure. A bill to decriminalize small amounts of marijuana is working its way through the lower house of Parliament, bringing threats from the White House that such a law could slow trade at the border.

Recently, while musing about his retirement plans, Prime Minister Jean Chrétien said he might just kick back and smoke some pot. "I will have my money for my fine and a joint in the other hand," he said with a smile. The glibness of the remark made it nearly impossible to imagine an American president uttering it. But in a nation where the dominant west coast city, Vancouver, has come to be known as Vansterdam, few Canadians blinked.

When Massachusetts's highest court ruled for gay marriage, the issue loomed over American politics. Conservatives vowed to change the Constitution. President Bush said he would defend marriage. Even the major Democratic presidential candidates backed away from supporting gay marriage outright.

Contrast that with Canada, where two provincial courts issued similar rulings this year. With little anguish, Canada became only the third country — after the Netherlands and Belgium — to allow same-sex marriage as a matter of civil rights.

Canadians themselves are not wholly united on the issue. Most elderly and rural Canadians express reservations, and the Canadian Anglican Church is almost as divided over homosexuality as the American Episcopal Church. Still, Canadians remain tolerant of the shift.

More than 1,500 gay and lesbian couples have married since the court rulings. "The Canadian reaction to same-sex marriage has been mostly positive," said Neil Bissoondath, an acclaimed Trinidadian-born Canadian novelist and social critic.

But the same issue in the United States "has upset the fundamentalist Christians who drive a lot of the politics in the country, especially with the present administration in power," Mr. Bissoondath added.

Rachel Brickner, 29, a political science graduate student at McGill originally from Detroit, said that despite her own liberal views, she sometimes tired of the anti-Americanism she encountered among Canadian students.

After the Sept. 11, 2001, attacks, she said, an old roommate told her that "the U.S. deserved 9/11 because we're bullies."

"Canadians are quick to blame the United States for not knowing about Canada," she said, "but Canadians make a lot of ignorant statements about the U.S." No Canadian city reveals differences as much as Vancouver. It looks like any American city, except for a drug culture that is so abundantly open. The police rarely interfere with bars, storefronts and even offices where people can buy or smoke marijuana. A "compassion club" distributes marijuana legally to cancer patients and others who have doctors' notes.

The city opened a publicly financed and supervised injection site for heroin users in September. The federal government, meanwhile, is preparing to start an experimental heroin distribution program for addicts in Toronto, Montreal and Vancouver in 2004.

The changes in marriage and drug laws, said Michael Adams, a Toronto consultant and polling expert, "means Canada is moving in the opposite direction with the United States and closer to Europe."

In his new book "Fire and Ice: The United States, Canada and the Myth of Converging Values," he argues that greater Canadian tolerance reflects a fundamental difference in outlook about everthing from the ethnic and linguistic diversity of immigrants to the relative status of the sexes.

Mr. Adams notes that weekly church attendance among Canadians has plummeted since the 1950's while American church attendance has remained virtually constant.

To many commentators the two countries seem to be exchanging their traditional roles, one founded in America's birth as a revolutionary country and Canada's as a counterrevolutionary alternative.

During the Depression, under the New Deal of Franklin D. Roosevelt, the United States was the progressive force, while Canada stubbornly held on to conservative economic policies.

By the mid-1960's, though, Canada shifted to a far more activist government, moving to a national health insurance system. Not long afterward, the Vietnam War began siphoning popularity from the Great Society experiment of President Johnson. The trends have only widened since.

Not all analysts see a big, lasting divergence. Some like Peter Jennings, the ABC News broadcaster who was born in Toronto and became a dual American and Canadian citizen in May, believe that Canadians have actually drawn closer to Americans. Nevertheless, Mr. Jennings said Canada had become "a socially more relaxed kind of place."

"Canada, as it is with some of the European countries," he added, "is trying to balance some of the market forces with public policy, which is not as apparent in the United States, where the pursuit of happiness and individualism are very much alive."

Still, a cultural gulf is widening.

"In the 70's we were taught Canada would be absorbed by the United States, and in the 80's it looked like it was happening," recalled Douglas Coupland, the Canadian author known for his cultural commentaries on both sides of the border. "Then came the latter part of the 90's and it was like some high school class 16-millimeter film where you see the chromosome duplicates, then realigns, and finally the cell splits.

"And that process only seems to be quickening in recent months."