Exposing the 'western' spies sent by the KGB to keep tabs on the Prague Spring

Kremlin's most prized spies were sent in to Czechoslovakia to watch and at times whip up the 1960s reform protests in a move then copied across the eastern bloc.

- By Shaun Walker

During the spring of 1968, as revolutionary sentiment began to grow in communist Czechoslovakia, a group of friendly foreigners began arriving in Prague, on flights from Helsinki and East Berlin, or by car from West Germany.

Among them were 11 western European men, a Swiss woman named Maria Weber and a Lebanese carpet dealer called Oganes Sarajian. They were all supporters of what would become known as the Prague Spring, an ultimately doomed attempt to build a more liberal and free version of socialism and escape from Moscow's suffocating embrace. Many of the visitors sought to get close to the movement's leading lights, offering support in the battle to reform communist rule.

But these visitors were not what they seemed. They were spies from the KGB's "illegals" programme – Soviet citizens who spent years training to be able to pose convincingly as westerners. Previously, illegals had been used to burrow into western societies and ferret out secrets for Moscow. But now the KGB was terrified that the Prague movement could end Soviet influence in the country, and decided for the first time to deploy its most prized spies inside the eastern bloc, in a mission called Operation Progress.To this day, Russia's intelligence services have never admitted it took place.

Unpublished documents about the mission, along with interviews with participants, shed new light on how Moscow used its spies to keep tabs on reformers in Prague: informing on its leaders, planting fake evidence and, in one case, getting a man who planned a dramatic self-immolation as protest committed to a psychiatric institution before he could carry out the deed.