The Kremlin-backed strongman of Chechnya has issued a stream of threats against Russia's liberal opposition, but his primary audience appears to be the Russian president himself.

With Ramzan Kadyrov's five-year stint as regional leader about to expire, he is trying to parlay his strong personal ties with President Vladimir Putin to extend his hold on power. The Russian president must now decide whether to keep him in place or yield to rising pressure from law-enforcement agencies to get rid of the wayward strongman, who has ruled Chechnya like his personal fiefdom.

Putin has seen the burly, red-haired 39-year-old former rebel as essential to keeping Chechnya stable after two separatist wars, and has given him privileges no one else in Russia's tightly controlled political system has seen. If he backs Kadyrov for another term, the Chechen leader is certain to easily win the popular vote set for September.

Kadyrov has converted his personal relationship with Putin into a steady flow of federal subsidies and immunity from federal controls. Even Russia's all-powerful security agencies have been forced to bow to Kadyrov's diktat, maintaining a symbolic presence in Chechnya but depending entirely on his will.

Kadyrov's unprecedented clout has worried many in Russia, who see it as a dangerous erosion of federal authority and a looming threat to the country's integrity. The Chechen leader's defiant posture also has won him numerous enemies among the leaders of law-enforcement agencies, but they have had to bite their tongues.

Things began to change when opposition leader Boris Nemtsov, a former deputy prime minister, was shot dead on Feb. 27 while walking across a bridge a stone's throw from the Kremlin. The brazen killing caused international outrage at a time when Russia-West relations were already at their post-Cold War low over the Ukrainian crisis, and it reportedly drove Putin mad.

Investigators quickly tracked down several people accused of involvement in the killing, all of them from Chechnya. The suspected triggerman was an officer in Kadyrov's security force, and his suspected liaison, another senior officer in the Chechen police, was a relative of some of Kadyrov's top lieutenants.

The killing offered Kadyrov's foes in the federal agencies a rare chance to finally get rid of the Chechen strongman, but Putin stood by him and the investigation has fizzled. Key suspects have disappeared and reportedly have been whisked abroad, and the investigators have failed to name the organizers.

As the one-year anniversary of Nemtsov's killing approaches, Kadyrov has gone on the offensive, launching a series of stinging attacks on Russia's liberal opposition on his Instagram account, where he has 1.6 million followers.

In language reminiscent of the Stalinist purges, he has denounced opposition leaders as "enemies of the people" working to destabilize Russia on Western orders. He has called for them to be put on trial or sent to psychiatric hospitals, a practice the Soviet secret police used against dissidents.

Kadyrov stepped up his attacks by posting a video featuring Mikhail Kasyanov, a former prime minister turned Putin's foe, and fellow opposition activist Vladimir Kara-Murza seemingly seen through the crosshairs of a rifle. The video appeared particularly ominous as Kara-Murza, a harsh critic of Putin and Kadyrov, nearly died last year of what he said was deliberate poisoning.

In the latest incident Tuesday, Kasyanov had a cake thrown in his face at a posh Moscow restaurant by a bunch of men some said were Chechens.

The Kremlin has kept a poker face, refraining from comment.

Some observers see the Chechen strongman's blustering rhetoric as an ingenious attempt to secure his job after his current tenure expires in early April. Everyone in Russia's political class knows that Putin never bows to opposition criticism or public pressure, so Kadyrov has strengthened his chances by drawing the opposition's outrage.

"On the one hand, this campaign has been aimed at the opposition, but on the other hand it has been addressed to the president," said Dmitry Gudkov, an opposition lawmaker. "It has been deliberately conducted in such a way as to cause a wave of anger and demands for Kadyrov's dismissal. Putin never makes decisions under public pressure, so it was necessary to create such pressure."

The statements from Kadyrov also serve as a demonstration of his unfaltering personal loyalty to Putin and a reminder of the punch he can pack for the Kremlin.

Kadyrov has described himself and his troops as "Putin's foot soldiers," and some Chechens have played a role in the fighting in eastern Ukraine, where they backed pro-Russia separatists against Ukrainian troops in the early stage of the conflict. The Chechen leader also has offered his services to the Kremlin on other fronts. This week, he said in a documentary made by Russian state television that he had sent Chechens to infiltrate the Islamic State group in Syria in order to gather intelligence.

The Chechen leader backed his statements by staging a massive rally in his support in Chechnya's capital, Grozny, which attracted up to 1 million people, according to local officials. While the attendance figure seems inflated, Kadyrov has enjoyed broad support in Chechnya, where people are tired of the turmoil and destruction of separatist wars. Many welcome stability and the new jobs created under Kadyrov's watch despite abuses by his feared police force, whom human rights groups accuse of abductions, torture and extrajudicial killings.

While he had Grozny's central avenue named after Putin, Kadyrov also has encouraged strict observance of Islamic rules in Chechnya, making it obligatory for women to wear headscarves in public. Men in Chechnya have been tacitly allowed to have several wives, a provision his critics have used to show that Chechnya under Kadyrov has morphed into a separate state governed by its own rules.

"Chechnya lives under its own laws, and the federal authorities lack any levers to influence Kadyrov," said Ilya Yashin, an opposition activist who was a friend of Nemtsov. "Kadyrov has used federal money to effectively create a regional army that answers not to Russian law, but personally to him."

While Putin may be willing to tame the Chechen leader, he is clearly at a loss on how to do it without plunging the region back into turmoil. Kadyrov's private army of several thousand troops is a major factor, and the Chechen leader long has exterminated all rivals, so the Kremlin would struggle to find a successor.

The hard-won stability in Chechnya is touted as a key achievement of Putin's rule, and the president would be unlikely to risk it by dismissing Kadyrov.

"With Chechen phalanxes, Kadyrov sends a warning to the Kremlin: I'm with Putin, I trust him and he trusts me," Alexei Malashenko, an expert with Carnegie Endowment's Moscow office, wrote in his blog. "But if something extraordinary happens, you don't complain, you see what kind of men I have under my command. You better be friends with me."