President Obama hosted Brazilian PresidentDilma Rousseff at the White House on Monday. One syndicated news story published before the presidential parley asked, “What could Obama learn from Brazil President Dilma Rousseff?” The optimistic answer is: hopefully not much. This relationship is not in America’s interest.

Ms. Rousseff is an exemplar of the anti-American hard left that is uniting in the developing world to check U.S. power. One of the main goals of her mission to Washington is to get Mr. Obama’s seal of approval for Brasilia’s ambition to acquire a permanent seat on the United Nations Security Council. U.S. support for this scheme would be self-destructive as Brazil would provide a reliable vote against American interests in the world body. Ms. Rousseff, a former communist guerrilla herself, is a strong supporter of anti-U.S. dictatorships such as the Castros in Cuba and Hugo Chavez inVenezuela. She has backed the Iranian mullahs’ efforts to acquire nuclear capability while leading a club of nations pressing for U.S. nuclear disarmament. If the planet is divvied up between those who are for us and those who are against us, Ms. Rousseff is on the wrong side.

Mr. Obama has nothing to learn from Brazil’s leader on the economic front, either. Before she came to power last year, the South American giant finally seemed to be crawling into the society of serious nations. Although an old-school liberal himself, Ms. Rousseff’s predecessor, former President Lula da Silva, took some big strides to improve Brazil’s business climate and standing among investors by updating infrastructure, working collaboratively with international nongovernmental organizations and pushing a moderately pro-growth economic agenda. The perception of progress helped Brazil win the 2016 Olympic games and the 2014 World Cup, a crowning achievement for a soccer-mad people.

Ms. Rousseff has taken an abrupt fiscal U-turn, however, by clamping down on markets, instituting miles of new red tape and ramping up government spending. Like in Obama’s America, the result has been dramatic economic decline. During the height of the Lula administration, confidence in Brazil’s direction led to predictions of long-term economic growth rates of 5 percent and higher. But under the new statist direction of the governing coalition led by Ms. Rousseff’s Workers’ Party, the economy has tanked, with 2011’s gross domestic product only growing by 2.7 percent, the lowest in South America.

Amazonian mischief is of interest to Americans because Brasilia’s stranglehold on its people and economy offers a cautionary tale about the threat unrestrained government power poses to democracy. The increasing persecution of the conservative group Tradition, Family and Property (TFP) exposes the dangers of dissent in the rapidly secularizing world. Founded in the 1960s to fight communism and promote traditional values, the TFP - which is well-known in Washington circles for its active U.S. affiliate - is Brazil’s leading opponent against leftist priorities such as abortion, censorship and regulations that inhibit private-property rights. Because it stands in the way of Big Brother, the government has gone after the TFP. Most recently, the Superior Tribunal of Justice, one ofBrazil’s upper-level courts, ruled in favor of a splinter group, the Heralds of the Gospel. The move, which occurred under strong pressure from church authorities including the Vatican’s apostolic nuncio, is effectively gagging the TFP by handing its assets over to liberal dissidents.

This tale matters because Brazil is now the world’s sixth-largest economy and a leader of the coalition of second-tier states looking to extract revenge for years of perceived Western “first world” imperialism. The narrative mirrors Mr. Obama’s kneejerk “Blame America First” worldview. Brasilia also shows how left-wing bureaucracies mobilize to stifle dissent through censorship and confiscation of property when faced with public opposition. This week’s confab between Mr. Obama and Ms. Rousseff was more than a photo-op for two leftists whispering about what the world could be if they had more power. It’s about what the world is already becoming.