Well yeah, it's an easy cop out to blame a country the other side of the world for your fellow countryman's treatment of aboriginals.
Introspection is hard; but deflecting the blame will do nothing to resolve the issue.
Edit: Australia gained Responsible government (IE: making their own rules independent of the UK; though subject to higher laws like taxes etc) between 1855-1890... with full autonomy granted in the 1930s.
So you lot have had around 100 years; and the treatment hasn't budged... Let me guess; still not the Aussies fault eh?