According to documents made public in 2012*, during the
falklands war the brazilian president-dictator General Figueiredo had planned to join the falklands war on the argentinian side if the UK had made any incursion inside the argentinian territory, first a transcription of the article I found:
"Brasília - Secret archives shows that the brazilian government alerted the USA that Brazil wasn't going to accept if british troops attacked the continental region of Argentina during the
falklands war. The documento, of which the state had access, narrates two meetings in may of 1982 between the president of Brazil, João Baptista Figueiredo, and of the USA, Ronald Reagan, and also the american secretary of state, Alexander Haig
The document is from the collection of the Concil of National Security, stored inside the national archive in Brasília, and got the rare classification of top secret
In the first meeting, in may 11, in Blair House - the offical guest house of the american president -, Figueired was only with Haig, preparing himself to meet Reagan in a presidential meeting two days later
Figueired, as Haig, regret that the conflict in the falklands had became a military dispute and both try to operate as moderators. But Figueired warns that the consequences could be way worse if the british tried to fight in the continental soil, instead of restricting themselves into the falklands archipelago
The brazilian general seems to suggest that such situation wouldn't be accepted in south america, and Brazil could even position itself military in the argentinian side..."
you can find the rest of the article
here, but it is in Portuguese
Well, here is the question: What if the british had raided the argentinian coast, or the argentinian military junta got in touch with Figueiredo's words and made a false flag attack inside argentinian territory to bring Brazil into the argentinian side, what would happen? Sadly I have no data of the size of the brazilian army and navy at the time, but Brazil had only one aircraft carrier, the colossus class
Minas Geraes bought in 1956