The news headlines this week brought a warm glow of nostalgia to anyone brought up during the 20th century’s Cold War.

The US shot down four UFOs which are suspected Chinese surveillance balloons. Not to be outdone, China accused the US of violating its airspace with spy balloons of its own.

It was widely known that embassies on both sides of the Iron Curtain maintained ‘diplomats’ whose real mission was to spy

In Britain, Prime Minister Rishi Sunak reassured us that the RAF were quite capable of dealing with hostile UFOs threatening our security, thank you very much.

Meanwhile, a London court sentencing hearing has heard how David Smith, a security guard at Britain’s Embassy in Berlin who was spying for Putin’s Russia, was trapped in an MI5 sting involving a fictitious Russian agent called ‘Irina’.

And in France historians announced that they had cracked the cyphers for scores of coded letters written in the 16th century by Mary, Queen of Scots during her long imprisonment by Elizabeth I which eventually ended in Mary’s execution.

Yes, there’s no doubt about it – espionage is back in fashion. But did it ever really go away?

The world’s second oldest profession reached its peak during the half century of the Cold War – a global duel fought by proxy between the Soviet Union and its communist satellites and the United States and its western allies.

The spy wars, glamourised by Ian Fleming’s James Bond novels and films, and more seedily and realistically depicted in the works of John le Carré, seeped into the consciousness of everyone on the planet.

It was widely known that embassies on both sides of the Iron Curtain maintained ‘diplomats’ whose real mission was to spy on their host nations and there were regular tit for tat mass expulsions of such spy staff.

Just as frequently, western traitors who had betrayed secrets to the Soviets for motives ranging from ideological conviction to money would be exposed and jailed, while western agents in Russia would be dealt with rather more drastically by being shot, or (so rumour had it) by being slowly fed live into a furnace.

When Soviet Communism collapsed at the end of the 1980s, spies found themselves out of work, and John le Carré started to write about drugs and the new war against Islamist terror rather than Karla and ‘Moscow Centre’.

This pause in the spy wars was to be brief. The Cold War soon resumed with the same old enemies of the West decked out in new clothes. While remaining nominally ‘communist’, China enthusiastically embraced capitalism and successfully challenged the US for global economic hegemony.

In Russia, a new strong man dictator emerged from the chaos that followed communism who openly regretted the demise of the Soviet Union and sought to reconstruct Russia’s old empire by increasingly bold military means, culminating in the invasion of Ukraine.

It is no coincidence that this ruler, Vladimir Putin, is himself a professional spy: a former KGB officer who uses the ruthless methods that he was schooled in – such as the murder of opponents by poison – as the tools of his trade.

With the arrival of the internet, a whole new front opened in the spy wars. Both China and Russia were accused of interfering in western elections using cyber warfare, while western outfits like the US National security agency and Britain’s GCHQ did their best to fight back – though constrained from using the more vicious methods employed by the other side.

Beneath the spy wars waged by the superpowers lesser conflicts continued unabated: Israel’s highly effective intelligence agencies Mossad and Shin Bet are thought to have carried on bumping off their Palestinian and Iranian enemies, while the rather less ruthless FBI and MI5 did their best to prevent outrages perpetrated by Islamist terrorists.

So the spies never really went away: they merely kept out of the news for a while.