Not only has it been said that Australians become racist, but also incredibly violent and tend to become criminals all in the spirit of National Pride
I would say nationalism is bad in all of it's forms, in any situation.
Nationalism is loving your own country to the point of hating everyone elses. If you're saying "that's nationalism in it's extreme form", then you DO NOT know the meaning of nationalism. What I described is nationalism 100%, in it's only form.