The emergence of the aforementioned trends (fears of a resurgent Asia and the subsequent appeasement policies; economic-political links with Asia; and, especially, the liberal-internationalist influencing of the younger generations) combined to imbue a large part of the "up and coming" new generation of politicians, businessmen, and community "leaders" with a pro-Asian outlook, underlined by a liberal-internationalist ideology of varying shades.
While it was Australia's post-World War Two fears of Asia, and the subsequent political appeasement of those countries, that led to the softening of the White Australia Policy for diplomatic and foreign policy reasons, it was the new middle-class (largely influenced by the post-war liberal-internationalist, "brotherhood of man", "peace" ideology) that came to destroy the Policy. Initially, using the non-racial veneer of the Policy (put there for foreign policy reasons - because of Australia's fear of Asia) as a weapon to demand and implement further changes to the immigration safeguards; then later gaining enough power so as to deliver the final death-blow to the White Australia Policy as a whole.
It was by working through the major political parties that the new middle-class immigration reformers were finally able to achieve their ideological aims. Firstly through the Liberal Party, by effecting the gradual softening of the Policy; then through the Labor Party, by gaining control of the Party, and subsequently destroying the White Australia Policy once in government.