Hours after Boris Nemtsov was slain on Friday night near the Kremlin, Russian President Vladimir Putin vowed to seek justice: "Everything will be done so that the organizers and perpetrators of a vile and cynical murder get the punishment they deserve," he said in a condolence message to the 55-year-old Nemtsov's mother. Whether Putin is being sincere is something only he and his closest advisors know. But Russia's recent history inspires little confidence that Nemtsov's killers, whoever they are, will be brought to justice.

Nemtsov was a high-profile politician, having served as a deputy prime minister and, more recently, as a regional legislator. He was such an outspoken critic of Putin in those roles that he openly feared for his life. Along with his colleague Leonid Martynyuk, Nemtsov published a report detailing the immense corruption surrounding the 2014 Winter Olympics, which were hosted in the Russian resort town of Sochi. Nemtsov also spoke out about Russia's seizure of Crimea last February and subsequent support for pro-Kremlin rebels in eastern Ukraine. But Nemtsov is hardly the first critic of Putin to lose his life to premeditated murder. Dozens of journalists have been killed since the Russian president first assumed office in 2000. Few of those responsible have been brought to justice—a point Nemtsov himself was well aware of. "The murderers understand that killing journalists is not a problem," he told Foreign Policy's Christian Caryl in a 2010 interview.

The assassination of a well-known politician, however, is somewhat more unusual. In an attempt to preempt public outrage, the Kremlin has already formed a committee to investigate the causes of Nemtsov's death. One possibility officials cited was that Nemtsov's commentary about the satirical publication Charlie Hebdo, whose offices suffered a murderous assault in January, made him a target of Islamists. The committee also mentioned Nemtsov's controversial position on Ukraine, and, most spectacularly, suggested that he was killed by fellow opponents of Putin in an attempt to rally opposition to the Russian president.

Putin's critics have not had it easy in Russia. A major economic slowdown triggered by falling oil prices has not diminished the president's popularity. The country's liberal opposition—epitomized by Nemtsov and the jailed politician Alexei Navalny—is weak and marginalized, and their positions on Ukraine, Putin, and the Sochi Olympics are not widely shared among ordinary Russians.

Nevertheless, the Kremlin appears wary of turning Nemtsov into a martyr. On Sunday, he was scheduled to appear at an anti-Putin rally in Moscow. But when the organizers asked to turn the rally into a memorial for Nemtsov, Russian authorities denied the request. Even so, protests have done little to challenge Putin's grip on power—something that Nemtsov himself acknowledged in a recent interview published in Newsweek's Polish edition:

[The liberals'] idea is the one of a democratic and open Russia. A country which is not applying bandit methods to its own citizens and neighbors. But, as I mentioned, Russian fascism is a hybrid. And hybrids are extremely resistant.

As the world mourns his death, Nemtsov's vision seems very far from being realized.