Looking back at the whole Brazil election (with likely "fortifications" by the CIA), I have to wonder if Bolsonaro did choose to cross the Rubicon if that could have sparked WWIII. I really doubt that countries like the US would not double down on making sure that the "correct" result was kept in place by sending their own military. And after that, all bets would be off with who else might decide to enter the fray. Which could mean WWIII.
Maybe all this would not happen, but I have to wonder.
@YoMomz Regarding the cause, I would say cowardice would be a factor. There is also a factor of denial. Not many would want to admit that we are in WWIII until it is too obvious to acknowledge. With the current small scale it is easy to deny that it would be happening.
Though perhaps that denial is a part of cowardice, but not always.