Vladimir Putin may well be seriously ill, or worse.

He hasn't appeared in public in a week, he just canceled a trip to Kazakhstan and a series of meetings in Moscow, and the hashtag #ПутинУмер (Putin Died) is trending like mad on Twitter. There have been reports in the Russian media that he's had a stroke.

Whether Putin is sick, or "is feeling fine," as his spokesman Dmitry Peskov insists, the system he presides over is far from healthy. Even if Putin the man is in top form, the "collective Putin," Russia's informal ruling circle, is showing signs of deep distress.

In fact, over the past two weeks, since the February 27 assassination of opposition figure Boris Nemtsov, it has appeared to be in the throes of a crisis. Informal rules have been violated, rivalries among figures near the top of the power pyramid have escalated into open conflict, and Putin has been conspicuous by his absence.

And while it is impossible for outsiders to truly know what is going on in the opaque world of the Kremlin's inner sanctum, there seem to be two possible explanations for Putin's disappearance from public view.

Either he is fine and furiously working behind the scenes to calm the clan warfare that has emerged in the wake of the Nemtsov assassination.

Or Putin is truly sick and incapacitated and the recent turbulence we have witnessed -- from the assassination to the muddled narratives in the investigation to the open conflict between the Federal Security Service (FSB) and Chechen leader Ramzan Kadyrov -- are symptoms of a highly personalized system that has lost its head.

New Rules?

In a political system like Russia's, where formal institutions are weak, court politics are paramount, and personal ties mean everything, obscure signals and gestures matter a lot. So do informal rules. They have to, because the law doesn't apply to those on the top.

This was one of the reasons why the Nemtsov assassination was so shocking. Killing somebody this prominent -- and certainly doing the deed blocks from Red Square -- was against the rules.

As Ivan Yakovina, a former political correspondent for Lenta.ru, wrote recently in the Ukrainian newspaper Novoye Vremya, "Moscow's unspoken rules" forbid killing those other top politicians. Even those such as Nemtsov, a former deputy prime minister, who had gone into opposition.

The killing, therefore, was "a signal to all representatives of this class," Yakovina added.

And if the Nemtsov assassination has violated one of the cardinal edicts of Putinism, the aftermath violated another: Clan warfare among top members of the elite must not be played out in public.

When the FSB named Zaur Dadayev -- a man with close ties to Kadyrov - as the mastermind of the Nemtsov assassination, it was interpreted in the elite as a direct assault on the Chechen strongman.

Kadyrov is powerful. Perhaps one of the most powerful men in Russia. He has thousands of loyal armed men at his disposal; he has a strong lobby in the Interior Ministry; he counts key Kremlin power brokers like Vladislav Surkov as his allies; and he has long enjoyed Putin's support.

But he has also acquired powerful enemies, including Kremlin chief of staff Sergei Ivanov, Kremlin political overlord Vyacheslav Volodin, and FSB chief Aleksandr Bortnikov.

And Kadyrov's enemies now appear to be using the Nemtsov assassination to take him down.

In a recent interview, the prominent journalist and Kremlin-watcher Oleg Kashin noted that it was significant that Dadayev and the other suspects in the Nemtsov case were arrested by the FSB and made public by Bortnikov himself.

"Up until now, Bortnikov was not a public person who announces somebody's arrest," Kashin said. "This is usually done by Investigative Committee spokesman Vladimir Markin."

This, Kashin added, also reeked of a "siloviki war" -- a showdown among the security services -- since Dadayev served as deputy commander of Battalion Sever, an Interior Ministry paramilitary unit formed by the Chechen leader.

"Bortnikov struck a blow against Kadyrov," journalist and political commentator Orkhan Dzhemal told Ekho Moskvy.

"There's a battle going on. The Spasskaya is fighting the Borovitskaya," he said, metaphorically referring to the two famous Kremlin towers.

Battle Of The Titans

The battle played out in media reports about the Nemtsov investigation, too. A report in the pro-Kremlin tabloid Moskovsky Komsomolets claimed that Dadayev had retracted his confession and claimed he was tortured

There was also a story in the opposition Novaya Gazeta that quoted unidentified law-enforcement officials who claimed the authorities know who really organized the Nemtsov hit -- a mysterious Chechen security officer, also with close ties to Kadyrov, identified only as "Major Ruslan."

In fact, the FSB assault on Kadyrov appeared to commence in earnest before the Nemtsov assassination.

In February, a Daghestani court sentenced two Chechens to nine and 12 years in prison on for plotting the assassination of Saigidpasha Umakhanov, a rival of Kadyrov's and the mayor of the region's third-largest city.

The FSB also took the lead role in that case. And in a report this week -- note the timing -- Novaya Gazeta quoted FSB officials as saying the assassination was ordered by Adam Delimkhanov, Kadyrov's cousin and close associate.

If a battle between Kadyrov and the FSB is about to go full-throttle, it would be a war of the titans that could shake the Putin system to its core.

And Kadyrov's behavior -- from his much-publicized trip to a shooting range this week to the statement he posted on Instagram where he wrote that he would lay down his life for Putin -- suggest that he senses the danger.

But for the time being, at least, Putin is nowhere in sight.

-- Brian Whitmore