It's nice to dream about how things were in the 1950's: cities were smaller, less cars on the road, less people, less pollution. However in the modern world, for an isolated country to be able to defend itself it needs a large, strong economy and a large population. It needs the large, strong economy to buy the very expensive military hardware. It needs the large population to be able to have a large military and also to be able to sustain heavy casualties in a war...and the wars do happen. As the economy grows, it needs labour to feed that growth. The amount of additional wealth that can be generated through agriculture or minerals which are capital intensive is limited. So whether anyone likes it or not, the population needs to grow. Whether anyone likes it or not, it will grow. That population growth can come about by people reproducing in Australia, or through immigration (or a combination of both). It was recognized last century that people were not having enough children in Western countries. In fact there was negative population growth. Because of the failure to populate naturally, countries such as Australia relied heavily on immigration. Now for those who don't like the high levels of immigration, you only have yourselves to blame for failing to populate.
