Russia’s supreme court has ordered the closure of Memorial International, the country’s oldest human rights group, in a watershed moment in Vladimir Putin’s crackdown on independent thought. The court ruled Memorial must be closed under Russia’s controversial “foreign agent” legislation, which has targeted dozens of NGOs and media outlets seen as critical of the government. Memorial was founded in the late 1980s to document political repressions carried out under the Soviet Union, building a database of victims of the Great Terror and gulag camps. The Memorial Human Rights Centre, a sister organisation that campaigns for the rights of political prisoners and other causes, is also facing liquidation for “justifying terrorism and extremism”. Memorial International’s closure marks an inflection point in Russia’s modern history, as efforts to publicise crimes under Soviet leaders such as Joseph Stalin have become taboo 30 years after the secret government archives were opened after the end of the Soviet Union. While not quite seeking a return to the Soviet past, Putin has become deeply sensitive to any criticism of it by groups including Memorial. Genri Reznik, a lawyer who represented Memorial on Tuesday, called the decision to close it “political”, adding that the hearing reminded him of the Soviet show trials of the 1930s. The decision also follows a sustained assault on Russian civil society this year that has led to opposition leaders such as Alexei Navalny being imprisoned, prominent activists and journalists fleeing the country, and NGOs and media outlets hit with fines and closures under Russia’s “foreign agents” and “undesirable” laws. The judge, Alla Nazarova, ordered the organisation closed for “repeated” and “gross” violations of Russia’s foreign agent laws, a designation Memorial has called politically motivated but nonetheless claimed to have followed. The decision will close the “Memorial International Historical, Educational, Charitable, and Human Rights Society, its regional branches and other structural units,” she said. In his defence of the organisation, Reznik said: “The Memorial Society promotes the health of the nation. To eliminate this from the history of the country now means to contribute to the idea of ‘the state is always right’.” The Interfax news agency quoted a lawyer for Memorial as saying it would appeal, both in Russia and at the European court of human rights. The Russian prosecutor portrayed the organisation as a geopolitical weapon used by foreign governments to deprive modern Russians of taking pride in the achievements of the Soviet Union. Those arguments dovetail closely with the Kremlin’s use of Soviet history as a rallying point for society and reinterpretation of key historical moments in its confrontations with European countries. “It is obvious that, by cashing in on the subject of political reprisals of the 20th century, Memorial is mendaciously portraying the USSR as a terrorist state and whitewashing and vindicating Nazi criminals having the blood of Soviet citizens on their hands,” said Alexei Zhafyarov, a representative of the Russian prosecutor general’s office, during the hearing. “Why should we, the descendants of the victors, have to see the vindication of traitors to their homeland and Nazi henchmen? … Perhaps because someone pays for that. And this is the true reason why Memorial is so fiercely trying to disown its foreign agent status,” he continued. About 100 supporters of the organisation gathered outside the court on Tuesday. Many chanted “shame” after the verdict was delivered. Police made several arrests. Memorial’s leadership had hoped the broad public support for the group might save it from closure. At a previous hearing, the group submitted more than 127,000 signatures in support of the organisation, as well as the testimonies of those who had discovered the fates of their relatives thanks to gulag and other records uncovered by Memorial. “The long-term activity of Memorial has always been aimed at restoring historical justice, preserving the memory of hundreds of thousands of victims during the years of repression, preventing such things now and in the future,” wrote the former Soviet president Mikhail Gorbachev and the Novaya Gazeta editor, Dmitry Muratov, in a joint statement last month. They called on prosecutors to recall their claim against Memorial. The purge of Russia’s opposition and independent organisations has continued through the end of the year. In the past week a BBC Russian journalist announced he had fled the country after being named a “foreign agent” and realising he was being surveilled, and OVD-Info, a website that monitors arrests and court cases, was blocked as a “foreign agent”. Two former coordinators for Navalny’s nationwide political network were also arrested on extremism charges on Tuesday. The daughter of Natalya Estemirova, a former Memorial board member murdered in Chechnya for her human rights work in 2009, wrote in response to the verdict: “My mother always used to say: ‘It can’t get any worse than this.’ Turns out it can.”