The immediate cause of the difficulties has been the fallout from the revelation that the National Security Agency had spied on the Brazilian president, Dilma Rousseff, and her subsequent cancellation of a planned state visit to Washington last October. Since then, relations between President Obama and the Brazilian leader have been frozen. Brazil wants an apology, which it will not get, or at least a significant American gesture, of which there is no sign. Unhappy with Brazil’s political direction, the Obama administration is not on the verge of a bout of contrition.

Prodded by Rousseff’s left-of-center Workers’ Party, Brazilian foreign policy has of late been as open-armed toward Venezuela and Cuba as it has been cool toward Washington. Following Venezuela’s admission in 2012, Mercosur, the South American trading bloc dominated by Brazil, has turned into a sort of anti-Yankee talk shop (in contrast to the Pacific Alliance, another newer trading bloc of more buoyant economies whose members, including Chile and Peru, are pro-American).

The 50th anniversary this year of the coup that brought military rule to Brazil, and led to the arrest of Rousseff, a leftist guerrilla fighter in her student days, has provided the occasion for more criticism of the United States, which was supportive of the army’s intervention. The spying scandal has spurred the facile notion that nothing has changed, when in fact just about everything has.