WHILE MOST of the world watches Russian President Vladimir Putin as he fuels separatist forces in Ukraine and curtails imports of Western goods, his growing repression of critics and independent organizations inside Russia is less noticed. This turning of the screws is the mirror image of the Kremlin’s foreign aggression, and it is more important to sustaining Mr. Putin’s regime than any of his sparring with the West.

Last summer, we were alarmed when hundreds of civil society organizations across Russia — groups that defended migrants, the environment, human rights, voting rights and other freedoms — were confronted with inspections by the authorities under a 2012 law that requires them to register as “foreign agents” if they engage in political activities and accept foreign funds. The law defined political activity broadly and vaguely, thus subjecting almost any organization to arbitrary targeting by the authorities.

Now, Mr. Putin is going beyond harassing inspections. When the law was first passed, dozens of Russian groups refused to register and fought the idea in the courts, with mixed results. In May, parliament amended the law, giving the Justice Ministry power to brand groups as “foreign agents” without their consent. Mr. Putin signed it in June. Then the government began to act — registering about 10 groups as foreign agents against their will. The term “foreign agent” has a deep and disturbing meaning from Soviet history. It was used in Stalin’s day to stigmatize and discredit people as traitors and spies, at a time when mere contact with a foreigner could be a pretext for arrest and execution.

The new designations are a KGB-like tactic to grind the organizations into oblivion. It didn’t take long for someone to spray-paint graffiti on the walls of the building that houses Memorial, a group that does human rights work and investigates and preserves the memories of Stalin’s crimes. “Foreign agent, Love, USA,” the graffitti declared. The selection of Memorial for this indignity is especially offensive; the organization has done more than any other to catalogue for future generations how people were mendaciously denounced as spies and foreign agents in Stalin’s day. The specific Memorial section that has been labeled a foreign agent carries out human rights work of the kind that Mr. Putin and his powerful acolytes in the Russian security services have long found discomfiting.

Even performance art tends to jangle nerves in the Kremlin. Recently, the authorities issued threats against two news outlets and blocked a Web page because they featured the views of Artem Loskutov, an activist and performance artist from Novosibirsk who has called for a demonstration advocating more autonomy for resource-rich Siberia. The authorities say this amounts to “extremism” and is prohibited. While Mr. Putin is encouraging and fueling separatist fighters in Ukraine, he does not like to hear talk about Siberia becoming more independent from Moscow, even as protest theater. Mr. Putin finds certain terms very scary. Free speech is one of them.