Canada just legalized marijuana. Should the United States follow suit? Or do you think Canada is making a mistake?

In “Canada Legalizes Recreational Marijuana, and a National Experiment Begins,” Dan Bilefsky writes:

MONTREAL — Canada on Wednesday became the first major world economy to legalize recreational marijuana, beginning a national experiment that will alter the country’s social, cultural and economic fabric, and present the nation with its biggest public policy challenge in decades.

On Wednesday morning, the government announced that it would introduce legislation to make it easier for Canadians who had been convicted of possessing small amounts of marijuana to obtain a pardon.

While the government is not offering a blanket amnesty, Ralph Goodale, the public safety minister, said at a news conference in Ottawa that as “a matter of basic fairness,” the government would seek to end the minimum waiting period of five years to apply for a pardon as well as waiving the fee of 631 Canadian dollars.

“We will make the application process as simple as it can be,” Mr. Goodale said, adding that details would not be available for several weeks.

Newfoundlanders became the first Canadians to be able to smoke pot legally on Wednesday, when retailers there opened in the country’s easternmost province at midnight.

Across the rest of the country, government-run stores were preparing to greet consumers, who will be able to choose among pre-rolled joints, fresh or dried marijuana flowers and cannabis oil — all of which are permitted under the new federal law.

At a government cannabis store in eastern Montreal, a line stretched across a long city block on Wednesday morning. Hundreds of people, some of whom had been waiting since 3:30 a.m. for the store’s 10 a.m. opening, waited, some smoking joints, filling the air with the pungent smell of marijuana.

As the first customers left the store with dried cannabis in brown shopping bags, the crowd cheered.

“I have never felt so proud to be Canadian,” said Marco Beaulieu, 29, a janitor. “Canada is once again a progressive global leader. We have had gay rights, feminism, abortion rights — and now we can smoke pot without having to worry police are going to arrest us.”

Kate Guihan, 29, a beautician, had been in line for hours.

She said she planned to celebrate the “historic moment” on Wednesday night with several puffs on a joint. The low cost of government pot, she added, was a big draw for her, along with the fact that legal marijuana was screened and devoid of contaminants found in some black-market marijuana.

“This is a great moment for Canada,” she said. “It will bring in money, help reduce the black market.”

Marijuana advocates were also jubilant about the day.

“The fact that we are moving away from a Prohibition model is a victory for human rights and social justice, an economic windfall for the Canadian economy and a sign of social progress,” said Adam Greenblatt, a director at Canopy Growth, a producer that has been valued at more than $10 billion.

Others were more cautious.

“Legalization of cannabis is the largest public policy shift this country has experienced in the past five decades,” said Mike Farnworth, British Columbia’s minister of public safety.