Our discussion touched on various countries. One of them was Uruguay, where a social democratic government of the moderate left not only offers an example of economic responsibility and democratic continuity, but stands at the vanguard on such sensitive issues as the legalization of marijuana. Brazil, the giant of the region, primarily owes its development in recent years to the linear succession of three presidents who represent a reformist and modernist left — a former Marxist theoretician (Fernando Henrique Cardoso), a radical union leader (Luiz Inácio Lula da Silva), and a former guerrilla fighter (Dilma Rousseff). Colombia, a country ravaged by the drug trade, leftist guerrillas and rightist paramilitaries, has reduced the level of violence and will probably soon sign a peace pact with the FARC, its oldest guerrilla organization. Chile, in spite of the political scars left by the coup against Salvador Allende and the dictatorship of Augusto Pinochet, is reaping some of the fruits of its republican traditions over the past two centuries.

Mr. Vargas Llosa argued that the “21st-century socialism” proposed by Hugo Chávez of Venezuela is not an attraction for the younger generations, that no one dreams any more of being Che Guevara. To make the point, he noted the country’s economic crisis — and the workers’ resistance to a regime that spreads lies, depletes the nation’s oil resources and tolerates corruption deep within the army. Such conditions, he contended, of course cannot endure for long, and must be fought by building strong institutions that uphold and respect the rule of law. He was hopeful that this could be done, all the more that today Latin America enjoys “a consensus on democracy and the free market, whether in its liberal or social democratic form.”

My position was somewhat different. I believe that Latin American populism — from Chavism to contemporary Peronism — is still a constant temptation amid the poverty and inequalities of Latin America. An affection for the policies of Eva Perón marks the populism of President Cristina Fernández de Kirchner of Argentina; much more wildly, the spirit of Hugo Chávez apparently speaks to Venezuela’s erratic president, Nicolás Maduro, by night in dreams and visions — and sometimes by day through symbols, like the chance appearance of a pigeon during one of his speeches. (Venezuela is a particularly sad case because of the stifling of civil liberties there, an alarming trend about which the Organization of American States, shamefully, has had nothing to say.)

And what of Mexico? I explained how entire regions of the country are in effect occupied by organized crime. The euphoria that accompanied the transition to democracy after the defeat of the long-ruling Institutional Revolutionary Party (PRI) in the 2000 election has faded and been replaced by considerable discord. After the poor record of the two governments under the conservative National Action Party (PAN), the return of the PRI to power has been seen by some as a regression. The left, which might well have won a turn in power in the 2012 elections, preferred a radical to a moderate candidate who could have appealed to a much larger slice of the political spectrum and been able to institute liberal reforms, much as the Brazilian left has done.

In the past year, the government of the PRI president, Enrique Peña Nieto, has succeeded in getting progressive legislation through Congress. In theory, the measures can serve to modernize the economy and further its growth, but many Mexicans are angry and see the government as merely a servant of national and international capitalism. The coming year will be decisive. Will these reforms be productively and honestly implemented? No less than the survival of Mexican democracy is at stake.