An unholy alliance is rattling the Kremlin

A high-profile alliance between Russian President Vladimir Putin and the leader of the Chechnya region of Russia is starting to fray. And outspoken Kremlin critic Boris Nemtsov, who was mysteriously gunned down in front of the Kremlin last month, reportedly knew all about it.

Critics of Putin say that over the past decade the Russian president has empowered 38-year-old Ramzan Kadyrov, the head of the Chechen Republic, "to effectively create the Islamic republic that Chechen separatists had dreamed of - albeit one entirely reliant on Moscow for financial support," The New York Times reported this week.

The Times notes that Putin has allowed Kadyrov to rule the region for eight years while "seemingly turning a blind eye to assassinations, torture and other human rights abuses." And critics, including Nemtsov, were warning about what happens if the warlord turned strongman's ambitions for power spin out of Putin's control.

"I cannot understand what Putin expects when arming 20,000 Kadyrovtsy gathered today in the stadium in Grozny," Nemtsov wrote in Facebook post in December. "What will happen next? The country is entering a crisis. There is not enough money for anything, including the support of regions.

"And the unspoken contract between Putin and Kadyrov - money in exchange for loyalty - ends. And where will 20,000 Kadyrovtsy go? What will they demand? How will they behave? When will they come to Moscow?"

It seems Nemtsov was on to something.

People initially suspected Kremlin involvement in Nemtsov's murder, but now five Chechens have been arrested in connection with the killing, and fingers are starting to point at Kadyrov as the possible architect of the hit.

One of the suspects arrested is a former deputy commander from one of Kadyrov's security battalions, which operate independently of federal authorities. Kadyrov praised the deputy as a "real Russian patriot" after he was arrested and implied that he wasn't guilty of taking a hit out on Nemtsov.

Moreover, four people familiar with the matter told Bloomberg that Putin was furious when he learned about what had happened.

Putin is "dealing with a significant internal challenge: It's extremely unlikely he ordered Nemtsov's killing, but it was clearly an inside job," Ian Bremmer, president of the Eurasia Group, told Business Insider earlier this month. "Dealing with that is surely his top priority."

Radio Free Europe noted that on March 16 - the day Putin reappeared from a mysterious 10-day absence from public view - a law enforcement official told Interfax that Nemtsov's murder had been reclassified from a "contract killing" to a "hate crime."

That designation all but squashes the investigation into who ordered the hit on Nemtsov. So while it's possible that the Kremlin's investigation might have ended up implicating Kadyrov in the murder, now it seems that possibility has been taken off the table.

In any case, Nemtsov supporters are now saying the investigation has "exposed a dangerous rift between the chiefs of the security services in Moscow and the brash Chechen leader," The Times says.

'The FSB hate Ramzan'

"The F.S.B. [the post-Soviet successor to the KGB] hate Ramzan because they are unable to control him," Alexey Malashenko, an expert on the Caucasus at the Carnegie Moscow Center, told The Times. "He does whatever he wants, including in Moscow. Nobody can arrest members of his team if there is no agreement with Putin."

Some experts think that Nemtsov's murder fits this context.

"Putin had to make a choice. Either feed Kadyrov to the FSB-men, or give up the FSB to Kadyrov," political analyst Leonid Volkov wrote on Facebook. "It's a difficult and unpleasant choice ... And he chose the one and only thing he could choose: Kadyrov."

An unnamed source close to the Kremlin told Bloomberg of another theory about Nemtsov's murder: that rogue FSB agents killed Nemtsov in the hopes of implicating Kadyrov, whose increasingly audacious actions have become a pain for officials in Moscow.

"Putin has become a hostage to his own policy of radicalizing supporters so they can spring to action whenever he needs them," Alexander Baunov, a senior associate at the Carnegie Moscow Center, told Bloomberg. "His authoritarianism is sliding into decentralized terror. His backers think he's much more radical than he really is and are acting without clear orders."

By giving Kadyrov the power to kill extremists in Chechnya in order to stabilize the region - as well as cover to assassinate perceived critics in the capital - Putin may have inadvertently created a monster that the Kremlin can't contain.

Nemtsov's supporters say Russian propaganda implicity encourages violence against Putin critics, according to Bloomberg. The Kremlin reportedly approved a rally in Moscow during which tens of thousands of people demanded that Putin's critics be "purged."

What happens next?

It's unclear whether there will be ramifications for whoever ordered the hit on Nemtsov. Or how the murder is rattling the Kremlin.

While Putin was absent from public view, Kadyrov reaffirmed his undying loyalty to the leader in an Instagram post, writing: "I will always be his faithful companion, regardless of whether he is president or not. To give one's life for such a person is an easy task."

Radio Free Europe points out that this could have been a veiled threat: "I am loyal, Kadyrov seemed to be saying. But others may not be. And taking me down carries risks."