ARTICLE 28 of the Russian Federation Constitution declares: “Everyone shall be guaranteed the freedom of conscience, the freedom of religion, including the right to profess individually or together with other any religion or to profess no religion at all, to freely choose, possess and disseminate religious and other views and act according to them.” Adopted in 1993 under Boris Yeltsin, this constitution looks increasingly tattered as President Vladimir Putin tramples the rights it guarantees. Now, the Russian authorities have taken another regressive step, muffling religious freedom.

On April 20, the Russian Supreme Court declared Jehovah’s Witnesses, a Christian denomination that rejects violence, an extremist group and banned it from operating on Russian territory, throwing the status of 170,000 members in 395 branches in doubt. The Witnesses will appeal, but if the order enters into force, those who continue to practice their faith could be subject to fines and imprisonment and the organization’s property confiscated. The Russian Justice Ministry earlier called the group “a threat to the rights of citizens, public order and public security” in Russia and put the Witnesses on a list of extremists, including al-Qaeda and the Islamic State, based on a 2002 law that the Kremlin has often used to bludgeon critics.

Mr. Putin’s style of authoritarianism is personal and intolerant, and insists on loyalty. The Witnesses believe in the superiority of their religion and eschew subservience to the state. They refuse military service, do not vote and view God as the only true leader. This may be one reason they are in the Kremlin’s sights. Their independence also worries the Russian Orthodox Church, an ally of Mr. Putin’s rule. In the Soviet Union, the Witnesses suffered decades of persecution, described by author Emily B. Baran in her book “Dissent on the Margins.” When Soviet authorities prohibited religious literature from crossing its borders, she recalled recently, “Witnesses set up underground bunkers to print illegal magazines,” and when barred from holding services, “they gathered in small groups in their apartments, often in the middle of the night. Sometimes they snuck away to nearby woods or out onto the vast steppe, where they could meet with less scrutiny.” The 1990s brought a promise of more religious freedoms under Yeltsin, but Ms. Baran notes that the unjust stigma attached to the faith in Soviet times was never wiped away, and Witnesses have suffered suspicion and mistrust in Russian society in recent years, as well as repression by the state, including a clampdown in Moscow.

By limiting religious freedom in this way, Russia turns its back on international norms and agreements. It also makes a mockery of the 1993 constitution, and not for the first time — the constitution also guaranteed a free press that no longer exists.