I think Megawati Sukarnoputri's not returning John Howard's telephone calls showed more gutlessness on her part than a snub. If she had the balls she would have made the contact and told him to take a flying leap, if that is what she felt.
Maybe a tactic as part of the "Shield of Steel" could be for spotter aircraft to leaflet drop likely vessels heading our way. The leaflet telling it like it is in different languages ie something to the effect that Australia has strict laws against illegal immigrants, the fact that they will be placed in detention centres until their eligibility for refugee status can be determined - and if they don't have passports or other documentation this will delay the process considerably - and if they are found ineligible they will be deported. Also detail the penalties for crew members manning the vessel.
That might make them think about proceeding further south -