As Brazil drifts away from America, increasingly siding with top global competitors, Washington is dispatching its United Nations ambassador to Brasilia, where she plans to chat about the weather — or, more specifically, the climate.  

Announcing Ambassador Linda Thomas-Greenfield’s May 2-4 trip, the American delegation to the UN said that while in Brasilia she will meet “with Brazilian government officials to discuss our partnership in the region and at the United Nations, including on climate and food security.”

Ms. Thomas-Greenfield will also visit the capital of Bahia state, Salvador, to talk about racial equality, and to explore ways to assist “250,000 Venezuelan migrants, refugees, and asylum seekers hosted by Brazil.”

Such issues may be important, but they are hardly pertinent to the competition between America and its top global adversaries, with which Brazil’s left-wing leader is increasingly siding. Sending a mid-level Cabinet member to Brasilia at this time is hardly a match for Beijing’s growing influence in the hemisphere. 

Brazil’s president, Lula da Silva, visited China in mid-April, sounding all the right notes for an ally of his host, President Xi — including the obligatory America bashing. “Every night I ask myself why every country needs to trade in the dollar,” Mr. da Silva said in a speech at Shanghai. “Who decided it was the dollar after the disappearance of the gold standard?” 

The speech was designed to launch an effort to boost the yuan in world trade and to unseat the American currency that has reigned supreme since at least the 1944 Bretton-Woods pacts. While at a lower level than in the past, some 60 percent of the world’s reserves are backed by the greenback.

Yet, under Chairman Xi Beijing has made it a goal to replace King Dollar with the yuen, and Mr. da Silva is striving to help his Communist ally in that endeavor. His Shanghai speech was on the inauguration of the New Development Bank. Headed by Mr. da Silva’s ally, Dilma Rouseff, a former Brazilian president, the bank’s top goal is to create a new currency for trade between Brazil, Russia, India, China, and South Africa — a bloc known as Brics.  

Communist China is by far Brazil’s largest trading partner and its main exporting destination. During his four-day trip there, Mr. da Silva was accompanied by 240 Brazilian business leaders. That grand tour stood in sharp contrast to a 48-hour White House visit, to which the Brazilian guest was accompanied by a handful of advisers.

Nevertheless, President Biden lavished his Brazilian guest with praise regarding restoring democracy to South America’s largest country and largest economy. He implicitly compared Mr. da Silva’s virtues to those of his right wing predecessor, Jair Blosonaro, who was a close ally of President Trump.  

While in China, Mr. da Silva signed 15 agreements with state-controlled tech conglomerates like Huawei, in the hope that the Communist regime will help him revive the moribund Brazilian economy. In contrast, the president drew the ire of the Brazilian press for returning from Washington with a relatively small pledge from Mr. Biden: $50 million designed to help stop deforestation in the Amazon. 

Mr. da Silva has indeed vowed to tackle deforestation and environmental issues as president, which could explain Ms. Thomas-Greenfield’s intent to discuss “climate” while in Brasilia. Yet, the topics she said would highlight her trip are much less crucial for the leftist president’s voters than Brazil’s economic woes.

On those, the Brazilian president is clearly banking on Beijing more than on Washington. Mr. Biden seems unconcerned about that competition.  

“My desire to increase U.S. manufacturing and jobs in America is not about China. I’m not concerned about China,” Mr. Biden said Wednesday. He was answering a question about the Chips Act, meant to boost the making of semiconductors at home.

As he launches his re-election campaign, the president may want to be more concerned about the growing competition with Beijing. Only 21 percent of Americans are satisfied with his China policy, according to a new Fox News poll. 

Meanwhile, following on his Chinese tour, Mr. da Silva is in Spain this week, promoting Mr. Xi’s and his own efforts to become the ultimate arbiters of peace in the Ukraine war. “It is of no use to say who is right or wrong, the war must be stopped,” he said, before comparing Russia’s invasion to America’s Iraq war.

Under Mr. Biden, America’s influence in important global spots from the Mideast to Latin America is fast eroding. Washington is yet to devise a strategy for what some see as a new Cold War, while Mr. Xi and his Russian and Iranian allies are making significant global strides. Sending Ms. Thomas-Greenfield to Brazil to talk about UN-centered side issues is unlikely to change that dynamic.