This is clearly a montage!
Why would anyone send poor Workers to the Antartic? Why was this transport trying to sneak it's way to the Atlantic instead of following the usual trade routes?
But
even if that was true (which I seriously doubt), what about the transport going up via the shores of Africa? And what about the Transports slowly getting close to Brazilian shores in the Pacific? Easter Island was already in range for a while now.
It was clear that Australia was mounting up some kind of plan against Brazil. The cold war was just a first sign. They were just unlucky that it was Brazil that got the first strike. The first strike was able to disable (or at least delay) their plans.
The first war was just a tactical strike against the local offender, as a statement that we mean business. Now... we are not holding anything back.