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.