what do you think were the motivations and justifications behind Australias "white australia" policy?

Answer 1

The "Yellow Peril" theory. Clearly people back then feared the teeming masses of Asiatics escaping the shackles of poverty. Check the old Australian national anthem, keeping Australian white and British was an important tenet to being an Australian citizen.

Answer 2

Fear of military invasion by Japan, the threat to the standard of living presented by the cheap but efficient Asian labourers, and white racism were the principal factors behind the White Australia movement. In 1901 the Immigration Restriction Act of Australia effectively ended all non-European immigration by providing for entrance examinations in European languages. Supplementary legislation in 1901 provided for the deportation by 1906 of the country's Kanakas. Popular support for White Australia, always strong, was bolstered at the Paris Peace Conference in 1919 when the Australian delegation led the fight to defeat a Japanese-sponsored racial-equality amendment to the League of Nations Covenant.

The White Australian people only inhabit the cooler coastal areas of Australia. The Japanese who had no problems with warmer climates, envied the vast land of Austalia which they felt would be useful for their ever growing population. Hence the fear of the White Australians.

Answer 3

A legacy from their original British masters. A subtle racism and xenophobia is woven throughout the history of the British Empire in its "management" of its colonies. it was the colonial administration of South Africa which put together the pass laws and other regulations of racial and tribal separation. When the South African government announced independence from Great Britain they merely put those measures on the law books, rather than having to re-invent the wheel.
Terms like "Wog", for "Westernized Oriental Gentleman", and "AngloBanglo" for a black person from a former British colony, persist today in ordinary speech. The current problems involving South Asian Muslims in Britain and Australia today can even trace its roots to the 1960s when a leading activity of street gangs was "Paki bashing" (assasults on South Asians).

Answer 4

Don't think of it as "racism." Think of it as cultural preservation. It is normal for people to try to keep their culture and way of life, and pass it on to their children. Surely no one would think it odd that Australian whites saw themselves as more closely related to other European-descended peoples, than to Asian ones. (Have China or Japan ever opened their borders to would-be immigrants?)