Michael,
The Australian situation is rather more tense than ours. They are just off the outer edge of the huge Islamic crescent that runs from the pillers of Hercules to the Phillipines, and this has coloured their thinking, quite rightly in my opinion. Also, their north-west quarter is a long way from population centres, empty and arid, but still part of their homeland. like us, any assessment of Australian attitudes is effected by population, distance and climate.
Add in their unfortunate experience in the Second World War, when the vast majority of their forces were in the Middle East and the UK at the time of Pearl Harbor. (Of their four infantry divisions, three were in the eastern Mediterranean and one was in Singapore, and thus, soon there were three) Despite pre-war promises from the Brits, the other formations were slow returning. One division was sent to Ceylon (Sri Lanka), not Australia while the others were retained in the Middle East for a long period. One fought at El Alemain in October 1942, ten months after the start of the Pacific War, and with large Japanese forces in New Guinea threatening Queensland and the Northern Territory. The situation was at least as bad for the RAN and RAAF. In the latter case there was not a single modern fighter aircraft in Australia.
Having an airborne capability gives them another option, and one that can be rapidly deployed.