Throughout history populations have migrated as a whole or in part. Australia and America are both nations that have experienced large population migrations to the point that the indigenous population was unable to maintain control of the land they occupied.

I am sure Italians in northern Italy felt violated when various tribes like the Lombards overran their lands. The same is true of the Gauls in France, when Franks overran their lands. Ditto, for England when Anglo-Saxons overran their land. More recently, the Russians and Poles seized huge parts of Germany after WW2, and the Jews seized parts of Israel that had long ago belong to ethic Semites (many Jewish) and more recently the land had been part of the Ottoman Empire.

At some level, there is a flawed concept that land belongs to one group or another or even an individual. History teaches the land belongs to the people that can occupy it and defend their borders. Even in countries like the US with private property laws, "the state" has a legal right to seize your land as it has "ultimate ownership" of all property within the borders it can claim control over.

There have always been two grounds to claim land, the strongest claim is the right of conquest. If you occupy it, you own it. The second is the right of discovery. Who were the first humans to inhabit a land. This latter claim is relatively hard to determine in most parts of the world, since these events occurred before recorded human history.

So, it is fair to say, the whites fought with the people occupying the lands of Australia when they arrived, but it is not automatically true, that they were the first to arrive there.

One can admire the Aboriginal people for attempting against the odds to hold on to the land they occupied.

These days it is far too simplistic to view the global conflicts as "racial ones", in reality, most wars of conquest were conducted by ethnicities against people of the same race. For a brief moment in history, Europe developed technological advantages that allowed them to expand their control over most of the globe, but as those advantages faded, so did their empires.

Their place was taken by the "new" indigenous people of the land. In some cases, they were the previous indigenous people and in other cases, they were comprised of a "new indigenous" people like the Palestinians of today.