It evoked the spirit of egalitarianism and irreverence that distinguished Australians from the English, with their class privilege and snobbery. But now the Islamophobes have filched most of the symbols of national belonging and I can't wear my T-shirt anymore.

Today the idea of clash of civilisations has given a nasty and combustible edge to national populism.  I didn't design the Southern Cross symbol, of course – that was the Ballarat gold miners at the Eureka Stockade in 1854 – but lately I've been feeling a bit like Jimmy Barnes.

Barnsey was appalled that his song Working Class Man has been turned into a xenophobic anthem. How could this happen? 

I'm as partial to a bit of Cold Chisel, as the next bloke so what should I do? Wipe their songs from the play-list? Stop ordering VB at the pub? Quieten down about beating the Poms at Lords?

We are currently in the middle of a national semiotic free-for-all. The Reclaim Australia supporters marched on the streets last week wearing Drizabone coats and cocky-farmer hats. 

One wore Ned Kelly's armoured helmet and others carried banners with boxing kangaroos. They shouted about preserving the Anzac legacy, defending women's rights ("the bikini not the burqa!") and fighting sharia, arranged marriage and polygamy. 

Some even waved Aboriginal flags in the faces of anti-racist protesters, and the anti-racists waved the same flags back at them. Go figure.

This exemplifies one of the key maxims of cultural theory: that authors can't control the way their texts are read/understood. The symbols and myths of nation are particularly volatile. 

Indeed many of the symbols of Reclaim Australia are about war and violence. There is something faintly rancid about angry young men purporting to defend Australian women's rights by attacking Islam. YouTube has numerous clips of such men calling on people to rise up and defend our way of life. This points to a deeper social problem of disenfranchised, post-industrial masculinity: working-class men for whom there are no working-class jobs. But ironically many of their Muslim scapegoats share the same fate.

While we are rightly worried that there are young Australian men of Middle Eastern backgrounds who go off to fight for Islamic State, we should also bear in mind that right-wing nationalists around the world are losing faith in the state's ability to keep this global threat at bay and some are inclined to take matters into their own hands. 

The example of Anders Breivik in Norway shows where such national paranoia can lead.