Could Russia's "dream team" turn into a nightmare?

MOSCOW (Reuters) - Some Kremlin-watchers have described it as a dream team: Russia's outgoing President Vladimir Putin moves into the prime minister's job and his protege Dmitry Medvedev takes over as head of state.

But many observers say a breakdown in the working relationship between the two men could destroy the stability the arrangement is supposed to safeguard.

"The existence of two rulers with two staffs is not a robust construction," said Vladimir Pribylovsky, an opposition activist and veteran political analyst.

"The entourages of the two co-rulers are already fighting with each other ... That will doubtless continue after the election."

For now at least, Putin's "operation successor" appears to be working like clockwork. Armed with an endorsement from his popular mentor, the 42-year-old Medvedev is almost certain to be elected Russia's next president in a March 2 vote.

And Putin, 55, who steps down in May, is poised to keep his hands on the levers of power by becoming prime minister in a Medvedev administration. Putin cannot stay on as president as the constitution bars him from serving three consecutive terms.

The uncertainty lies in whether the unusual arrangement will be effective: Putin is Medvedev's mentor but as prime minister he will be in a junior role answering to a younger man who has for years been in his shadow.

It is especially unusual for Russia with its tradition -- reinforced by Putin in his eight years of office -- of strong leaders who do not welcome rivals for their power.

Medvedev this month offered reassurances it would work. "Don't worry," he told Itogi news magazine. "The president-prime minister tie-up will prove its effectiveness."

POWER-SHARING RISKS

Others are less confident. "The elites in Russia only really pay attention to one leader, regardless of their title," the Nezavisimaya Gazeta daily said in an editorial.

"There are ... some very obvious flaws and risks associated with this power-sharing arrangement," said Chris Weafer, chief strategist at Uralsib bank. "Differences in terms of handling problems and the prioritizing of reforms and spending are inevitable."

Russian history holds many examples of joint rule ending in disaster. The uneasy co-habitation of last Soviet leader Mikhail Gorbachev and first Russian President Boris Yelstin hastened the collapse of the Soviet Union.

When a few years later Yeltsin fell out with his vice-president Alexander Rutskoi, their argument ended with Yeltsin ordering tanks to shell the Russian parliament.

But there is historical precedent too for effective power-sharing, said Roy Medvedev, one of Russia's most distinguished historians who during Soviet rule wrote a dissident history of Stalin called "Let History Judge."

The first example, he said, was when Tsar Nicholas II in effect shared power with Pyotr Stolypin, his powerful prime minister who until his assassination in 1911 kept a lid on revolutionary unrest and pushed through land reforms.

Under Soviet rule, Communist Party General-Secretary Leonid Brezhev shared power with Alexei Kosygin, chairman of the Council of Ministers.

Medvedev said that for a decade until he resigned for health reasons in 1980, Kosygin controlled the economy and represented Moscow abroad while Brezhnev ran the party.

"From these two examples you can draw the conclusion that for Russia such a system is possible," said Medvedev.

"Russia is such a big country that ... two people, if they are decent and good people, can tolerate each other for quite a long time provided they divide up spheres of responsibility."

(Editing by Janet Lawrence)