A mural painting by graffiti artist Eme Freethinker features likenesses of US President Donald Trump and Chinese premier Xi Jinping. Picture: AFP/John Macdougall
A mural painting by graffiti artist Eme Freethinker features likenesses of US President Donald Trump and Chinese premier Xi Jinping. Picture: AFP/John Macdougall

On April 22 1915, German artillery fired 5,730 canisters of chlorine gas at the trenches in the Ypres Salient occupied by soldiers from France, Algeria and Canada.

About 160t of gas drifted across the front in a 6km-long and 1km-deep fog, killing men in a manner that the barbarity of machine-gun slaughter and obliteration by high explosive had not quite matched: chlorine gas victims, unable to breathe, drown in their own fluids.

"Operation Disinfection" marked the first large-scale use of poison gas in warfare.

It was the new terror weapon, and soon everyone was doing it.

The trouble with gas, as both sides regularly found out to their horror, was that it didn’t care if the lungs it killed were German, English, Algerian, Russian or whoever. Sometimes the clouds of gas would turn back on the attackers as the wind changed direction in the middle of a barrage. A flippant American might call it being bit by your own dog.

Keeping that particular dog on a tight leash is the inherent problem with bioweapons: they can kill you just as quickly as they do your enemy.

That fact seems to have escaped both US President Donald Trump and secretary of state Mike Pompeo, who claim to have evidence that Sars-CoV-2, which causes Covid-19, was manufactured in a lab in Wuhan.

Neither man has offered any proof of their claims, with Trump saying, like a naughty schoolboy: "I can’t tell you that. I’m not allowed to tell you that."

Even the office of the director of national intelligence, which runs the US’s spies, disagrees with the commander-in-chief, saying that it agrees with scientific consensus on the virus’s natural origins.

Even if there had been research into coronaviruses going on at the Wuhan Institute of Virology, it’s a long way from the commander’s stumble of logic to making bioweapons. For who would unleash a weapon that would destroy not only your enemy’s economy but – because you make all the stuff that your enemy buys – yours as well?

History is full of tyrants pulling the temple down on their heads, but they were usually deranged, stupid or both.

Oh. Wait.