MEXICO CITY — With a swipe of his pen last week, Mexican President Enrique Peña Nieto proposed that Mexican citizens could legally possess up to an ounce of marijuana.
The day before, Canada’s health minister stood at a United Nations podium and announced that her country would introduce new federal legislation to make cannabis legal by next year.
Already, people are free to smoke marijuana in four US states and the District of Columbia, and medical marijuana is allowed in almost half the country. Uruguay has fully legalized weed for sale. And a large chunk of South and Central America, including Brazil, Peru, Chile, Colombia, Ecuador, and Costa Rica, has made marijuana more available in varying ways, whether it is for medicinal or recreational use.
In the shift toward legalization of marijuana, the Americas have emerged as a leader. This is a remarkable shift for a region that includes some of the world’s leading producers of marijuana, coca, and opium poppy, and where the US government has spearheaded a decades-long campaign against cultivation of the substances.
‘‘It’s undeniable that the terms of the debate about drugs are changing in Mexico and in the world,’’ Peña Nieto said during a speech Thursday announcing his new legislative proposal. ‘‘Fortunately, a new world consensus is gradually emerging in favor of reform.’’
For many Mexicans, the prospect of such reform seemed unimaginable just a few years back. Using illegal drugs has long been taboo in this conservative, predominantly Catholic country — as is true in many other Latin American nations. Drug-trafficking groups have inflicted horrific violence on the country, with an estimated 100,000 people dying in the past decade as the cartels have battled for control of shipping lanes to the United States. Polls have shown that a majority of Mexicans oppose legalizing drugs, fearing it would increase addictions and crime.
To have a Mexican president come out publicly in favor of loosening drug laws struck many people as historic.
‘‘This was the breaking point,’’ said Jorge Díaz Cuervo, a Mexican economist and politician who recently published a book on the prospect of legalizing marijuana. ‘‘There is now a before and after.’’
Peña Nieto’s initiative would make it legal for anyone to own up to 28 grams of marijuana — or one ounce — as long as it was intended for personal use. It would also permit the use of marijuana for medicinal purposes and make it easier to free prisoners who are being held on minor drug charges. The move came after five public forums held across Mexico this year to solicit public opinion and expert testimony on the prospect of changing drug laws.