THEIR nation is not OUR nation.
Remember that Islamofascists are also Fascists, and they don't even believe in national borders.
Simply substitute an ideology in place of a geographical nation, and Antifa meets all the parts of the definition of Fascism.
Islamofascist is not a generally accepted category. It’s popular with those right-of-center in their politics, but not broadly accepted.
Fascism, however, is a generally accepted term. Inherent in the definition if Fascism is a nationalism that is militant and aggressive.
Now, don;t get me wrong. I think that certain countries that were labeled “fascist” don;t fit this description. For example Franco’s Spain was not a militarily aggressive state. It was certainly a nationalist movement that sought to preserve traditional Spanish culture.