I’d guess New Zealand or Canada. The US has affection from a safe distance, but not attachment. Australia has had a majority narrative of Britishness until the 60s, but it had an undercurrent of resentment of Britain and Republicanism for the better part of the preceding century, fed in part by its large Irish population, and in part by its robust nationalism.
The cultural and economic break came in the 70s, triggered by the UK joining the Common Market, and Gough Whitman coming to power.
Like many Australians on the Left, I miss Paul Keating. The last of the visionaries. And one of the long tradition of Irish Australian Republicans. Here he is in 1992, combining two of his great loves: mocking Tories, and repudiating anglophilia.
I cannot imagine a New Zealand or an Anglo Canadian talking like this. I can imagine a Quebecois.
Or an American.