Australia state border closures: Closing due to a single case feels like 'security theatre'

"Victoria records zero new COVID-19 cases."

It was the headline on The Age website which finally got to me. As I read it on my phone I was sitting on a plastic garden chair in a draughty tent outside the Royal Adelaide Hospital, on an unseasonably cold day for a South Australian summer. Rain was falling and a sharp wind was infiltrating the tent, while I waited for two hours for a COVID-19 test.

That requirement had been suddenly sprung by the South Australian government on arrivals who had been in Melbourne at any time since January 28. A city which I now read had recorded zero new cases, amid the "crisis" caused by a single case contracted by a hotel quarantine worker. Meanwhile, the Northern Territory had declared Melbourne CBD a "red zone", meaning I was suddenly banned from boarding my train north.

With such tiny numbers, why exactly was this necessary?

I have no problem complying with measures designed to effectively stem the spread of the coronavirus. I lived through the eventually successful second Melbourne lockdown, after all, and have had three COVID-19 tests along the way. It's been heartening to see us all doing our bit on behalf of each other, to stem the tide of this modern-day plague.

But this time, it felt like "security theatre". You'll remember that from airports: seemingly random rules about whether liquids should stay in luggage (domestic flights) or outside (international) during screening; whether shoes should stay on or off; whether iPads stay in the luggage or not. You couldn't help suspecting that some of it was just for show.

And so it is with the Australian states' ever-spiralling reaction to the virus, in which entire cities and regions can now be locked down because of a single new case (sometimes a potentially more contagious strain, but still a single case).

Such lockdowns have a chilling impact on domestic tourism, but even worse is the backdating of measures. If people get on a flight knowing they'll have to get tested at the other end, that's one thing. But to arrive in a place and be enjoying your stay, only to suddenly be thrown into self-isolation or even quarantine based on a single new case back home, seems a step too far. Such retrospectivity is dubious in its effectiveness. Has anyone subjected to it ever turned out to be infected? Maybe some sensible risk assessment could be applied instead.

To be fair, in allowing me free access to Adelaide if my day 1 test came back negative, the South Australian government was being more reasonable than some. I arrived in the city on the Great Southern train from Brisbane, and was shortly due to board The Ghan north to Darwin. But the Northern Territory government abruptly declared my home suburb a COVID hotspot because that one infected bloke had spent half an hour in a bottle shop there a week before. So now I'm staying an extra week in Adelaide to board the next train, as by then I'll have been more than 14 days outside Victoria – the threshold beyond which the NT will let me enter without quarantine.