more on the
The Hague Convention on the Civil Aspects of International Child Abduction. the convention makes sure that signatory countries have to send back a child/children to its previous country of residence if that country asks for it. refusal is possible
this means that japan or a japanese court does not have to send back an "abducted" child. there are plenty of these cases involving japan and many countries is putting continuous pressure on japan to become a signatory. japan has so far refused. [personal opinion]not japan's proudest moment[/personal opinion]. japan is the only G7-member not being a signatory. it is also the only "rich" country except for singapore that has not signed the convention. (pls, don't ask me for a definition on rich).
ozkai, if she manages to leave australia for japan with your child chances that you will
never see your child again are unfortunately very big. also keep in mind that it wouldn't surprise me if she could just get a new passport for both herself and your son again at the japanese embassy. this is not exclusive for japan.
now, concerning your US colleague, what she did is against the hague convention and therefore the US, as a principle, will have to send back the child to japan if they request so. it is usually not to your advantage if you have abducted your child in a court.