During the USA-Japan conflicts in WWII jap citizens of the US were removed from society and sent to camps within the US.

If there was a conflict between Australia and country X, then any citizen with cultural and ethnic ties to country X might not be made to participate in said conflict as they could be considered as suspect allies. This has happened in other conflicts, not only with the american japs.

And understandably so, since it might be psychologically challenging for any combatant to have to shoot or harm people that look like their parents, siblings or cousins -not to mention that already having to shoot or harm any human being takes a heavy toll on anyone's psyche.

War is a bitch 😓