There's a scene that comes early on in the 1996 movie Independence Day.
Will Smith's character, a kind of handsome everyman who happens to be a fighter pilot, wanders out in his pyjamas, morning coffee in hand, to his letter box to get his newspaper (how quaint). As he glances up, he sees his neighbours scurrying around packing their cars with suitcases. He looks more closely at the front page of the paper, then out at the view.
Spread out before him is Los Angeles, over which hovers a gigantic spaceship. It casts a shadow over most of the city.
Then throughout the movie, we see the same kinds of spaceships lurking over other global cities - Sydney, London, Paris. The world unites to fight the aliens, and they win (thanks particularly to Will Smith - surprise!).
It's that concept - the world uniting to fight a common enemy - that has continued to bring this scene back into my mind over the past month or so.
When was the last time the whole world (well, most of it - there are still some outliers in complete denial), agreed upon the biggest and most urgent threat to their very existence?
There was perhaps a hint of this in recent times in response to climate change. Flood after bushfire after drought had moved it front and centre on the Australian agenda in a way we'd never seen before, and it appeared that its long politicisation - climate was a left wing concern, while right-wingers doubted its seriousness (to put it very baldly) - had started to break down.
Around the world, environmental activism was surging, and Greta Thunberg was its Joan of Arc - a little girl with a big cause who was rallying the troops.
Now that common cause has been dropped, just like every other cause on earth, as we turn to face another threat.
A Jordanian friend once told me this proverb: "Me against my brother; me and my brother against my cousin; me and my brother and cousins against the stranger."
She claimed it as especially Jordanian, but - and this is not a word of a lie - an Egyptian friend disagreed and they got in an argument about it. I wanted to point out the irony, but I didn't want both of them to turn on me.
The adage appears the very essence of tribalism, but it also illustrates how quickly and easily our enemy's enemy can become our friend, when it suits us.
And so it is - surprisingly - a virus that has finally united us against a common enemy. This one has no guns or bombs but is nevertheless devilishly tricky at getting through our defences.
There's been a lot of war talk in relation to COVID-19. World leaders have used the language of battle, as they sit in their parliaments and enact legislation allowing them to bring in emergency powers. Police and soldiers around the globe are oscillating between fining people eating kebabs on park benches and shooting curfew-breakers on sight.
But in other ways this global unity thing is a sham.
Yes, many wealthy countries are pouring billions into finding a vaccine or a treatment, and supporting the victims of their own gasping economies. There are heart-warming scenes of Italians singing across alleyways and Brits dancing (badly, it has to be said) in their driveways.
But the countries who were at war with each other before are still at war. Only now they have a potentially devastating virus to contend with as well. With borders shut and urgent needs in our own countries, our ability to look outside and be moved by the plight of Syrian refugees or starving Yemeni children will be severely curtailed.
It's possible that there has not been an event in our lifetimes that so cruelly throws into relief the difference between rich and poor. Most of us are sheltering in our homes and bemoaning the wobbly internet or the lack of online groceries. It's almost facile of me to point out what a privilege that is.
The fact is, we do have a common enemy, but some of us have better weapons of war than others, and I don't expect we'll share them.