Does speaking Portuguese isolate Brazil from the rest of Latin America?

When the Netflix original drama Narcos debuted in 2015, it instantly drew a cult following. That is, except for Colombia, where the story is set. That’s because drug kingpin Pablo Escobar, born and raised in the Medellín area, was portrayed by Brazilian actor Wagner Moura – who, prior to being cast as Escobar, had never spoken Spanish in his life. Moura’s thick accent was too much for Colombian viewers.

Brazil is the only Latin American country with Portuguese as its official tongue. Nine of our...