If free societies don't want to defend - they are conquered by the oppressed societies, and cease to be free.
And it's not like in modern Europe there are no wars (Russia-Ukraine for one example), or aggressive dictatorships (Russia, Turkey, less agressive but 100% dictatorship Belarus, and a few more dictatorships in making, all of them using nationalism as the building block).
I wrote it's "less agressive", but it's still a dictatorship.
Of course, Indonesia isn't likely to invade - it has enough trouble keeping itself together; all the decent economic bits of Australia are on the far fringes of the continent; and the US Navy would finally get the chance to engage in a maritime war, so they'd be in like Flynn to help out.
Defending your country is - as far as I'm concerned - a very specific case of fighting for your country.
Also - defending a country (a more or less random historical entity with potentially largely different political and ethical views even among residents) shouldn't be conflated with defending your home.
For me the former is abstract and quite artificial. The latter is literally the place where I live.
I expect the answers is highly correlated with "is the next war your country involved defending from an aggressor or being the aggressor?".