Can we trust our spies’ claims about Russia?

In the Spring of 1988, the body of Britain’s most notorious Cold War spy was lowered into the ground at Kuntsevo cemetery on the outskirts of Moscow. Kim Philby’s defection to the Soviet Union, a quarter of a century earlier, had rocked the world of espionage. Western spooks were left scrambling to work out just how much sensitive information he might have handed over. For a brief moment, a spotlight fell on the secret circles of informants, shady deals and double-agents.

Now, spies are once again coming out from the shadows and grabbing headlines. Over the past few months, officials in the UK and US have made a series of bombshell disclosures, citing classified intelligence and warning that Russia could be on the brink of ordering an invasion of neighbouring Ukraine. With satellite imagery handed out to the media purporting to show more than 100,000 soldiers massing on the border, London and Washington have begun laying on cargo planes carrying weaponry to Kiev, and preparing sanctions in case the Kremlin launches an offensive.