Putin's People by Catherine Belton review – relentless and convincing

This is the most remarkable account so far of Putin's rise from a KGB operative to deadly agent provocateur in the hated west

In 1985, a young KGB officer arrived in provincial East Germany. His name was Vladimir Putin. What exactly Putin got up to in Dresden is a mystery. The official version says not much: he drank beer, put on weight, lived in an ordinary apartment with his wife, Lyudmila, and their two daughters. While other Soviet spies were having adventures, Putin - so the story goes - sat out the late cold war in a paper-shuffling backwater.

The investigative journalist and former Financial Times reporter Catherine Belton has dug deeper. Her groundbreaking book, Putin's People: How the KGB Took Back Russia and then Took on the West, offers a far more terrifying version. Putin was a senior liaison officer with the Stasi, East Germany's secret police, she suggests. And Dresden was a key base for KGB operations, including murderous ones, in which Putin allegedly played a direct part.