Bad Korea and Japan at least hypothetically have immediate security interests to protect, at least from their own perspective. The UK is the dead corpse of an Empire playing at it's old glories so it'd probably be doing insane shit even without the US.

Canada and Australia are both extremely insulated from any possibility of war or violence but are still trying to start shit with China over nothing. Of the two, Australia has far more to lose economically, so I think by process of elimination the Aussies are fucking up the hardest.