Russian President Vladimir Putin, right, heads a State Council session alongside Russian Prime Minister Dmitry Medvedev in Moscow last year. Increasing political attacks on Medvedev have accompanied Putin's suspicions about his erstwhile partner's ambitions.
The attacks have come from many directions. One of the harshest was an anonymous, documentary-style film that was posted on the Internet in January.
The film, Game at Giveaway, accuses Medvedev of betraying Russia's national interest. It refers to the Medvedev's decision as president not to oppose the U.N. resolution that authorized NATO military action in Libya.
Why, the announcer asks, did Medvedev give away all of Russia's interests in Libya, its military and civilian contracts, and its friendly relations with Libyan leader Moammar Gadhafi?
Why, he asks, did Medvedev take away the gains made by Putin and give them to Russia's main rival, the West?
The film calls for Medvedev to be court-martialed.
Other attacks have been aimed at the prime minister's staff members.
Analysts note that Medvedev gets less coverage on state television these days and reports about him often focus on problems and failures.
The prime minister himself frequently expresses his esteem for Putin. For example, in an interview with CNN, Medvedev calls the president his "friend and colleague" and stresses that Putin is now fully in charge.
Lately, Putin has done very little to return the love or to defend his erstwhile partner against attacks.
Nikolay Petrov, a political analyst who teaches at Moscow's Higher School of Economics, says Medvedev is "a weak man."
"He's dead in [the] political sense, and I think that his position is very, very uncomfortable," he says.
The root of the problem goes back to 2008, when Putin served two terms as president and was constitutionally blocked from running for re-election. Petrov says that Putin needed someone to occupy the president's chair until he could run again — someone loyal who could never muster the strength to seize power for himself.
Though Medvedev was loyal and cautious, Petrov says, he still became a magnet for a budding Russian opposition that was looking for an alternative to Putin.
"I think that Putin miscalculated the fact that although Medvedev was a weak leader, he served as a banner for the camp that was pushing in the direction of political modernization," Petrov says.
That was enough to arouse Putin's suspicions.
The suspicions may have been aggravated in 2010, when Medvedev aides said he was considering running for a second term as president.
That question was put to rest in September 2011, when Medvedev proposed Putin as the nominee for president at a congress of the ruling United Russia Party.
Medvedev said that he was willing to serve as prime minister.
The announcement touched off anti-government demonstrations from opposition members who said the swap was making a mockery of the democratic process in Russia.
Andrey Piontkovsky, an independent political analyst in Moscow, says Medvedev's apparent weakness poses the awkward political question of why he is still prime minister.
Piontkovsky says the answer is simple: that Putin is merely waiting for an opportunity to fire Medvedev at a politically advantageous time — for example, when a crisis occurs that would be convenient to blame on the prime minister.
But Piontkovsky says Putin will need to be careful in his selection of the next prime minister because his own power depends on the ability to balance the conflicting factions in his government and keep any potential successor from getting too powerful.