WHEN the KGB men came to his family flat, they split up Yaroslav Sivulsky and his parents into separate rooms. Mr Sivulsky, then a young boy in the Soviet Union, watched as agents searched their belongings for “banned literature”. His grandparents had been exiled to Siberia for belonging to the Jehovah’s Witnesses, a Christian denomination founded in America in the 19th century; his parents had kept the faith alive in their home.

Now Mr Sivulsky and the 175,000 other Jehovah’s Witnesses in Russia face the prospect of returning to an underground existence. On April 20th, the Russian Supreme Court outlawed the group’s activities, declaring it an “extremist” organisation. “It’s all happening again,” says Mr Sivulsky. “Back then they came after us for ideological reasons, and now because our faith is not of the ‘right kind’.”

The ruling puts the group, whose members preach non-violence and refuse to serve in the military, on the same legal footing as several neo-Nazi groups. Lawyers from the Russian Ministry of Justice argued that they pose a threat to “public order and public security”. The group’s property and assets are set to be seized. Any organised religious activity will be considered illegal, with violators facing steep fines and even potential prison sentences. If implemented, the decision would be “by far the most severe blow to religious freedom in Russia since the end of the Soviet Union”, argues Geraldine Fagan, author of “Believing in Russia: Religious Policy after Communism”.

The ruling is a testament to the growing influence of the Russian Orthodox church, especially of a radical wing who see the Jehovah’s Witnesses as a dangerous sect that deviates from the official version of Christianity. The court’s decision marks the culmination of a long and concerted campaign. Experts trace the latest wave of troubles back to 2009, when Orthodox activists and local authorities began aggressively pursuing members and congregations. Regional courts steadily added Jehovah’s Witnesses literature to lists of banned extremist works, often on absurd premises. (One pamphlet was flagged for a line criticising the Russian Orthodox church. It was a citation from Tolstoy, whose works are not exactly banned in Russia.) The group’s refusal to participate in militaristic state rituals further fuelled suspicion. “The campaign dovetails with the drive for greater security, unity and patriotism,” says Ms Fagan. “Otherness and dissent are seen as threats.”

The Orthodox church’s complaints found support among Russia’s security services, which see the Brooklyn-headquartered Jehovah’s Witnesses as a nest of pernicious foreign influence. Valery Malevany, the vice president of a security service veterans’ group, suggested that Jehovah’s Witnesses and other Christian groups were “financed by Western special services” in order to carry out “sabotage” and “intelligence work”. Vitaly Milonov, an ultra-conservative MP, said Western governments were using the group to further their goal of “destroying our country through spiritual and moral decay”. Roman Lunkin of the Centre for the Study of Religion and Society at the Russian Academy of Sciences sees the crusade as part of “a wave of suspicion and fear regarding the West”. In recent years, Russia’s courts have declared more than 140 non-governmental organisations “foreign agents” for receiving money from abroad. “Now it has come to religion,” says Mr Lunkin.

It is not clear whether the decision portends a wider crackdown or will remain an isolated incident. The Jehovah’s Witnesses came under attack in part because they presented an easy target, argues Mr Lunkin. Members do not vote, are staunchly pacifist, and enjoy little support among a population that bristles at their door-to-door proselytising and unfamiliar theology. But the ruling is unlikely to cause believers to lose faith. “Who are we supposed to listen to now?” Mr Sivulsky muses. “The unjust decision of the court, or God?”

Correction (May 8th): An earlier version of this piece said that Mr Milonov accused Western governments of promoting “moray decay”. In fact, it is “moral decay”. Apologies.