Alexander Litvinenko didn't mince words. On Oct. 19, at a public meeting in London, he introduced himself as a former Russian kgb officer, and proceeded to accuse President Vladimir Putin of sanctioning the murder two weeks earlier of a crusading Russian journalist, Anna Politkovskaya. Litvinenko, who fell out with his erstwhile employers after claiming they had ordered him to assassinate Boris Berezovsky, an oligarch and high Russian official of the Yeltsin years, now exiled, had met Politkovskaya on several occasions. At one of their last meetings, he said, she had told him about threats she'd been receiving. "She asked, 'Do you think they can kill me?'" Litvinenko told a rapt audience at the Frontline Club, a British organization that promotes independent journalism. "I told her quite frankly: Yes, they can." Litvinenko ended with his accusation. "I know that a journalist of her stature could not be touched without sanction from the Russian President himself," he said. "Anna was a political opponent, and this is why she was killed."

It was a moment of high drama, but it paled beside what happened next. Last Thursday, Litvinenko himself died in a London hospital, after having ingested a "major dose" of the radioactive toxin polonium-210 that destroyed his immune system, according to Britain's Health Protection Agency. Scotland Yard said that traces of polonium-210 — which is so rare and volatile that producing quantities large enough to kill requires access to a high-security nuclear laboratory — were found at a sushi restaurant called Itsu in Piccadilly where Litvinenko had eaten lunch on the day he got sick. Traces of the isotope were also found at his north London home and at the Millennium Hotel in Grosvenor Square, which he had also visited.

Exactly how or why the dose was administered, and by whom, remains a mystery. The Litvinenko case revived memories of perhaps the most notorious assassination carried out during the cold war, the 1978 murder in London of Georgi Markov, a Bulgarian dissident who was working for the bbc. He was killed with a ricin-tipped umbrella while waiting for a bus, in a case that has never been solved. Just as in that Markov case, the death of Litvinenko has already given rise to a flurry of conspiracy theories, including speculation among defenders of Putin's government that the poisoning had been arranged by Russian exiles or Western intelligence agencies to discredit Moscow.

But Litvinenko — when he was alive — and his friends had little doubt about who's to blame. In a message dictated two days before his death and read out by his friend Alexander Goldfarb to the press, Litvinenko, 43, said: "You may succeed in silencing one man, but the howl of protest from around the world will reverberate, Mr. Putin, in your ears for the rest of your life."

Before Litvinenko died, a spokesman for the Russian Foreign Intelligence Service stated bluntly that he was "not the kind of person for whose sake we would spoil bilateral relations [with Britain]," and a Kremlin spokesman said talk about any possible role it may have had in the affair was "sheer nonsense." Sergei Yastrzhembsky, Putin's chief envoy to the European Union, suggested that the murder might be part of "a well-orchestrated campaign or plan to consistently discredit Russia and its leader." Asked about the matter at a Russia-E.U. meeting in Helsinki on Friday, Putin described it as a tragedy and offered his condolences to Litvinenko's family, but he questioned whether the deathbed note was genuine and said he hoped the case wouldn't be whipped up into "a political scandal." Russia stood ready to help British authorities with their investigation, he added.

Whatever the final outcome of the cases, the deaths of Litvinenko and Politkovskaya have chilled Russia's already frosty civil society, and revived memories most Russians would prefer to forget. Back in the bad old days of Soviet rule, fear was prevalent. People who spoke up against Kremlin authoritarianism knew what to expect: harassment, isolation, imprisonment and worse. Most people dared to grumble only in the relative safety of their own kitchens, but a hardy few — advocates of freedom such as Andrei Sakharov and Natan Sharansky — made their dissent public.

In the 15 years since the Soviet Union collapsed, Russia has been transformed; it's now much richer, more democratic and infinitely more open than it was. But, to the alarm of many Russians and some in the West, the old fear is returning. It is fueled by such things as the lists of targeted Russian activists that circulate on the websites of shadowy ultranationalist groups, and also by recent measures taken by the Putin administration, including a squeeze on the independent press and new laws that could be used to silence opposition voices. "There may no longer be shortages of groceries and long lines at every street corner, but Russia today is still a place where human rights and freedom are in short supply," says Ludmilla Alexeyeva, a doyenne of Russian human-rights activists, who co-founded the important Moscow Helsinki Group in 1976. "People who question the policies of our government are increasingly targeted. People who work for human rights are increasingly under attack. So, are we in Russia? Are we back in the U.S.S.R.?"

It's a startling question, but not all that far-fetched. Russian democracy, chaotically vibrant just a decade ago, is looking increasingly fragile as checks and balances to Kremlin power are dismantled. Regional governors and members of the upper house of parliament are no longer elected but appointed; no new political parties can exist or be started, unless endorsed by the Kremlin; it is no longer possible for independent candidates to stand in constituencies for election to the Duma. The continuing conflict in Chechnya has given rise to a slew of allegations about human-rights abuses. And there's a strong impression — real or not — that free speech is potentially dangerous once again, especially if it is used to openly criticize the President or highlight alleged abuses taking place under his aegis.

Not all Russians are falling silent; indeed, a new generation of dissidents has come into being. For many of them, such as Lidia Yusupova, the war against a separatist movement in Chechnya, which has rumbled on with appalling cruelty since 1994, has been a spur to activism. Yusupova helps victims of the violence in Chechnya and has assisted in documenting atrocities there, a job that has won her two human-rights awards and a nomination for this year's Nobel Prize. She has no illusions about the risks involved. "Dying sooner or later is not the issue," she says. "But it's important where and how you die. This feeling helps bridle fear."

Important though the conflict in Chechnya has been in focusing activism, Putin's political opponents have a long list of other grievances. They include allegations of torture by the police, pressure on journalists, and what opponents see as an erosion of Russia's democratic institutions. The ranks of the new dissidents are swelled by unlikely recruits — men such as Alexei Kondaurov, who, as a major-general of the kgb's Fifth Main Directorate, was responsible for crushing ideological subversion in Soviet days. Kondaurov is now a member of the Duma's Communist Party faction, and campaigns tirelessly on behalf of his friend and former employer, Mikhail Khodorkovsky, who once headed Yukos, Russia's biggest private oil company. Khodorkovsky is currently in jail after having been convicted on tax evasion and fraud charges that he says are bogus. "I'm amazed at myself," says Kondaurov. "A former kgb major-general, and yes, I do feel I'm a dissident now." He says that many former colleagues equate him with Pyotr Grygorenko, a top Soviet officer who was expelled from the party in the 1960s and confined to a mental asylum for expressing anti-Soviet views.

Kondaurov and others argue that the Russian authorities are terrified of the sort of "people power" that brought Viktor Yushchenko and Mikhail Saakashvili to power in Ukraine and Georgia. He sees a new dissident movement as "the only option," because power in today's Russia is now so concentrated in the hands of the Kremlin that any other opposition is futile. "It's very much the same as the case was in Soviet times," Kondaurov says.

Yet that familiar refrain is not the whole story. Some of the parallels being drawn between now and the days of Soviet rule are rhetorical and overblown. Those who are ill at ease in today's Russia for whatever reason can choose to live and work abroad (indeed, many of Putin's critics have decamped to London); an earlier generation could only dream of such freedom. Still, Kondaurov's feeling of claustrophobia — what Victoria Webb of Amnesty International describes as "the shrinking space for individual voices in Russia" — now appears to be widely shared. This year, Stanislav Dmitrievsky was prosecuted and saw his human-rights group, the Russian-Chechen Friendship Society, closed down after its newsletter reprinted speeches by Chechen separatist leaders. Amnesty International contends that shuttering the society "appears to be the latest move in a carefully calculated strategy to get rid of an organization that has been outspoken on behalf of victims of human-rights violations in Chechnya." Dmitrievsky himself says that Russia is veering away from democracy and back toward authoritarianism. "It's obvious after the Politkovskaya murder that no one is immune. We're all walking under a falling ax now," he told Time.

Dmitrievsky and others are seeking to protect and reclaim freedoms won in the final years of the Soviet Union, when Mikhail Gorbachev introduced his policy of glasnost, or greater openness. Later, in the immediate post-Soviet era, Boris Yeltsin presided over a scrappy, imperfect democratic flowering. Activists say that, since he took office in 2000, Putin has tried to bottle up the explosion of interest in human rights, free speech and democratic accountability that took place in the 1990s. Says Vladimir Ryzhkov, one of the few remaining independents in parliament: "The regime has achieved a state of total manipulation of the people." Most key media outlets, especially national television, are in the hands of the state or of Putin's close allies. In today's Russia, it is hard to find a newspaper that is truly independent and uncowed, which is why the fearless investigative reporting of Politkovskaya was so remarkable. Just recently, Vladimir Rakhmankov, the editor of a Web magazine in the city of Ivanovo, was fined $750 for a satirical critique of Putin's plans to boost birthrates in Russia. (Rakhmankov slyly noted that foxes, bears and other animals breed at the city zoo because they are well looked after.) It was only thanks to the intervention of a press-freedom group called the Center for Journalism in Extreme Situations that Rakhmankov wasn't jailed, as local prosecutors had demanded. "Our lawyers are always swamped with legal actions taken against local journalists, mostly on trumped-up charges," says Oleg Panfilov, the Center's founder.

Critically, this year has seen two pieces of highly controversial legislation. One law requires all nongovernmental organizations (ngos) to reregister with the state and submit detailed plans about their activities; a second revises an earlier law that attempts to control political extremism. (Both were used against Dmitrievsky.) Putin has said that the extremism law will improve Russian security in an era of terrorism, while Foreign Minister Sergei Lavrov asserts that the ngo legislation is actually less restrictive than similar laws in France, Finland and Israel. Foreign groups such as Amnesty International and Human Rights Watch that have reregistered say the process is cumbersome and bureaucratic, though so far only three foreign ngos have had their credentials rejected, and all can reapply. But the real test will come in the next few months, when Russian ngos go through the same process.

By any standard, however, the past few weeks have been grim ones for activists. In addition to the deaths of Politkovskaya and Litvinenko, Lev Ponomarev, a veteran campaigner, was arrested and jailed for three days in late September for organizing a memorial for the victims of the Beslan school hostage tragedy. His crime: holding an unauthorized rally. In early October, Manfred Nowak, a United Nations rapporteur on torture, was forced to postpone a fact-finding trip to Chechnya and the northern Caucasus after he was told that his intention to visit detention facilities unannounced and interview detainees would contravene Russian law. A human-rights activist in Ingushetia had her nose broken when a demonstration to commemorate Politkovskaya was dispersed by police. Dmitrievsky's organization was shut down. "October had me holding my head in my hands," says Allison Gill, who heads the Moscow office of Human Rights Watch.

Has anyone noticed? Some dissidents complain that, now that the cold war is over, Russia can get away with anything. "At least in the Soviet Union times there was a steady drumbeat of people in the West talking about the problem. Today, lots of Russian activists feel isolated," says Gill. That's not to say there's no support; the European Union and the Council of Europe hold regular discussions about human-rights issues with Russian authorities, and Angela Merkel, the German Chancellor, recently raised the matter of Khodorkovsky's imprisonment directly with Putin, saying the conditions of the oil boss's detention were "unacceptable."

But at a time when Russia is emerging as an energy superpower and a key ally on handling Iran and North Korea, human rights and freedom of speech are no longer at the top of the West's agenda. Some, including Merkel's predecessor, Gerhard Schröder, are quick to defend Putin; in his recent memoirs, Schröder described the Russian President as "a flawless democrat." "It's frustrating that some European leaders hold this view," says Grigory Pasko, a former navy captain, journalist and environmental campaigner who in 2001 was sentenced to four years in jail on treason charges, and released in 2003. "You would hear less of this sort of thing if Europe were not so dependent on Russian energy."

Not all is bleak. Western leaders may be less inclined to support dissidents than they once were, but it is easier than ever for those opposed to Putin to get their message out. In Soviet times, dissidents had to smuggle their news and thoughts to a wider audience through surreptitious meetings with foreign reporters or crudely printed tracts. Today, any blogger with a grievance can become a dissident, and the Internet is the new samizdat. And in the past two years alone, Russians have lodged almost 20,000 individual grievance cases at the European Court of Human Rights in Strasbourg, France; some of the most significant relate to abuses in Chechnya. "Yes, we're pushed to the kitchen again — but this kitchen is so much bigger than the one we used to have," says Dmitri Furman, 63, an intellectual from the Russian Academy of Sciences' Institute of Europe. In the 1990s, Furman wrote critical commentaries about politics and society for leading Russian newspapers. Today, no newspaper will take his pieces, but he sees some hopeful signs. "The network of liberal dissent in Russia is powerful," he says. "It is really beginning to realize how hopeless the existing regime is. It is also exhausting its own illusions, about Western help in particular."

Conceivably, the deaths of Politkovskaya and Litvinenko will awaken the West to the realization that all is not well in the new Russia. A Russia that is prosperous, in which there are goods in the stores and food on the table — that is a Russia that is in the interest of all the world. But a Russia where the powerful — whoever they are — feel free to defend their prerogatives in any way they choose is one that brings back bad memories. Russia's leaders should not be surprised if they discover that, outside its borders, those who have wished the country well as it has emerged from the long nightmare of communist rule remember the years of poison and the gun — and shudder at what is happening now.

• PETER GUMBEL
• Much has changed in Russia since the end of Soviet rule. But the mysterious death of former KGB spy Alexander Litvinenko, a recently vocal critic of the Kremlin, has raised fears among the country's new dissidents