An investigator wearing a camouflaged protective suit, gloves and a gas mark works with a police investigator in a protective suit in Rollestone Street outside the John Baker House Sanctuary Supported Living in Amesbury, southern England, on July 6, 2018 in connection with the investigation after a man and woman were found unconscious in circumstances that sparked a major incident after presumed contact with what was later identified as the nerve agent Novichok. Police on July 6, 2018, raced to find the object that contaminated a British couple with the Soviet-made Novichok nerve agent in southwestern England where a former Russian spy was poisoned with the same toxin four months ago. / AFP / Chris J Ratcliffe Image Credit: AFP

I am a child of the Cold War. I remember growing up dimly aware of nuclear weapons, and the idea that they could blow us all to smithereens. But chemical weapons? They were for the history books, the stuff of Wilfred Owen and monochrome soldiers on Pathe newsreels. No danger there.

Perhaps, then, bewilderment contributes to the shock and fury at the latest news from Amesbury: How could this happen? Had not chemical weapons themselves been consigned to the grave? Can they truly be back — not in the trenches but on our streets — to kill again?

Invisible, the Novichok threat is made all the worse. For all their stoicism, people around Salisbury will be asking themselves whether they and their children are safe. They will sit less easily on park benches, at school desks. Every headache, every fever, will cause alarm.

And so a targeted assassination has become an act of terror. A brutal murder attempt, designed to eliminate a political enemy, has ended up sowing entirely justified fear among innocent civilians. One extraordinary consequence is that the England football team may play Russia this week, in Russia, with thousands of fans enjoying the hospitality of a nation that has effectively committed an act of war against Britain. It is as if Britain had been playing Argentina in Buenos Aires in 1982, just as the junta invaded the Falklands. For despite its invisibility, its deniability, and its appeal to the conspiracists and fake newsers in Moscow and beyond, we can trace the origins of this Novichok outrage. We know the Russian lab that produced the nerve agent. We know the Russian scientists who designed it.

Even so, Russian President Vladimir Putin is partly right: Those in the West are to blame. Not for the manufacture and delivery of the ghastly molecule of course — responsibility for that is not in doubt. But they are culpable for allowing a climate in which chemical weapons can be used with such abandon.

On Monday, August 20, 2012, the then president of the United States, Barack Obama, had held an impromptu news conference at the White House. He uttered these words: “We have been very clear to the [Bashar Al] Assad regime that a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilised.”

Almost exactly a year later, in the early hours of Wednesday, August 21, 2013, rockets containing sarin gas were fired into rebel-held areas of Ghouta, a suburb of Damascus. US intelligence assessments put the civilian death toll at more than 1,500.

That is an astonishing figure. But the West did nothing. Ten days after the Ghouta gas attack, British members of parliament voted against taking military action in Syria. Much of the blame fell on Ed Miliband, though crucially 30 Tories also opposed the motion. Paddy Ashdown, former Royal Marine and intelligence officer, immediately declared himself “depressed and ashamed” (though nine Liberal Democrat MPs opposed too). “Chemical weapons will become more commonplace in the Middle East battlefield,” Ashdown said presciently. “We will feel the effects of that as well.”

It took just four years. In 2017, North Korea brazenly used VX — more deadly still than sarin — to assassinate Kim Jong-nam, exiled half-brother of dictator Kim Jong-un, in Kuala Lumpur airport. Then came the attack this March on the Skripals in Salisbury, Britain. A century-old chemical weapons taboo had been blown away as quickly as it takes World Cups to roll around.

Can it be restored? The sad truth is that re-drawing the red line will be incredibly hard. Coordinated allied air strikes against Syria in April began the process, by declaring impunity over. The bigger win has gone largely unnoticed, however. Last month, Britain led a global coalition to overcome Russian resistance and grant the independent Organisation for the Prohibition of Chemical Weapons the power not just to identify chemical weapons, but also to attribute blame for using them. Initially this remit can be used only in Syria. Amesbury shows how crucial it is to extend it globally. The world must now ensure that happens.

Meanwhile, we must learn that nothing is worse for national security than not following words with actions. “Speak softly and carry a big stick,” Teddy Roosevelt used to say. Britain shouted loudly and turned away. Today it is paying the price.

— The Telegraph Group limited, London, 2018

Harry de Quetteville is the Telegraph’s Special Correspondent, Technology.