Because Japan is the largest creditor nation in the world (ie it has the biggest positive Net International Investment Position).
Australia on the other hand, even with its low federal government debt, recently saw its negative NIIP to GDP ratio go past the level Thailand reach (60%) just prior to triggering the Asian financial crisis, depleting its foreign reserves and causing a 54% Thai Baht currency devaluation...
I'm not saying Australia is on the verge of currency crisis (or am I?)...
Main point is, I'm less worried about Japan than I am the country (Australia) that has one of the worst NIIP positions in the world, collapsing exports, falling terms of trade, an unpopped property bubble, 25 years since the last recession and with most things being financing on a AAA credit rating...
