When Robert Menzies rose to his feet to announce the findings of a defence policy review in April 1957, our most royalist of prime ministers shoved sentiment aside to declare the military would shift to predominantly sourcing American arms.

Menzies made the hard-headed strategic calculation that Australia’s geographic location and treaty obligations under both ANZUS and to South-East Asia (SEATO) meant “that in the event of war we will be fighting side by side with the United States”.