* Call for Assad to cede power a barrier to Russian backing at U.N.
* Putin determined to avoid precedent as he plans Kremlin return amid protests
* Moscow signals ready to veto resolution if left unchanged
By Steve Gutterman
MOSCOW, Jan 28 (Reuters) - Russian warnings to the West and its Arab allies to keep their hands off Syria hide a slight chance for compromise on a U.N. resolution aimed at halting bloodshed in the country, but a demand for President Bashar al-Assad to step aside could be a deal-breaker.
With Prime Minister Vladimir Putin facing the biggest protests of his 12-year rule and planning to return to the Kremlin in a March presidential vote, Russia wants to avoid stamping its approval on any regime change engineered from outside.
Moscow has been busy drawing "red lines" as it comes under pressure to stop shielding its old ally Assad and to use its power as a veto-wielding U.N. Security Council member to push Damascus into ending the crackdown which has killed thousands of civilians.
Russia has erected a wall of noise, emphasising it opposes sanctions against Syria - a major customer for its arms - and making clear it will block any attempt for the Council to endorse military intervention.
The latest test of Russia's resolve, a new draft resolution backed by Western and Arab powers led by Saudi Arabia and Qatar, does not call for new sanctions or threaten military action - but it does call for Assad to cede power.
The draft says the Council supports an Arab League plan "to facilitate a political transition leading to a democratic, plural political system ... including through the transfer of power from the President and transparent and fair elections."
Moscow could potentially be appeased if the draft's supporters remove the specific reference to the transfer of power by Assad or add a clause ruling out military intervention.
However, it may also demand a clear statement that Assad's more violent opponents share blame for the bloodshed. Russia would also be pleased by the removal of a clause calling for "further measures" if Syria does not comply swiftly, wording that to Moscow smacks of sanctions.
Gennady Gatilov, a deputy foreign minister, said on Friday that Russia would not support a demand for Assad's resignation and warned that a rushed vote would be doomed to failure, indicating Moscow could veto the draft in its current form.
Putin has said little publicly on Syria for months, letting diplomats do the talking, and President Dmitry Medvedev is formally responsible for foreign policy.
But Putin, who is expected to win a six-year Kremlin term despite a drop in popularity from previous highs, is widely believed to be guiding Russia's Syria strategy.
Russia and China used a double veto in October to block a Western-backed draft resolution condemning Assad's government for its crackdown on pro-democracy protesters and opponents, which the United Nations says has killed more than 5,000 people.
Western diplomats say Russia might find it difficult to veto a resolution they say is simply intended to provide support for the Arab League, whose efforts to end the Syrian violence have generally been welcomed by Moscow.
But Sergei Markov, a university vice president and former lawmaker with Putin's party, predicted Russia would also veto the new Western-Arab resolution if its call for Assad to give up power remains. "For Russia, this is intervention in domestic poltics and part of a strategy of regime change," he said.
Russia has adamantly warned the West it would not allow a repeat in Syria of last year's events in Libya, where NATO military intervention helped rebels to drive longtime leader Muammar Gaddafi from power.
Moscow had let the NATO air operation go ahead by abstaining in the U.N. vote that authorised it, but then accused the alliance of overstepping its mandate to protect civilians.
Putin has angrily likened the Libyan resolution to "medieval calls for crusades", and last month suggested Gaddafi was hounded to his death with the help of NATO special forces and U.S. pilotless drones.
Russia has plenty of pragmatic reasons to resist political change in Syria, one of Moscow's strongest footholds in the Middle East since the Soviet era. Syria has been a major client for Russian arms sales and hosts a naval maintenance facility on its Mediterranean coast that is the only base outside the former Soviet Union for Russia's shrunken navy.
More importantly, analysts say, Putin needs to be seen to be standing up to the West and making clear that the internal affairs of sovereign states, including Russia, are off-limits to foreign interference.
The call for Assad to step aside is particularly objectionable for a leader who, since coming to power in 2000, has answered U.S. and European charges that he has rolled back democracy with accusations of Western meddling and told his citizens to guard against efforts to foment revolution in Russia.
"For Putin, the language is unacceptable, because it sets a precedent," said Vladimir Frolov, president of LEFF Group, a Moscow-based government relations firm.
To many Russians, he said, "Putin would look inconsistent, weak and stupid if he were to authorise the Foreign Ministry to support that. He's been saying the opposite to his supporters on the stump."
Putin has turned to anti-Western rhetoric repeatedly during his campaign for the March 4 vote.
Facing criticism over a December parliamentary vote that many Russians suspect was rigged to favour the ruling party, Putin accused the United States of stirring up a persistent street protest movement that have undermined his authority.
He told students in Siberia on Wednesday that the United States "wants to control everything" and seeks to make other countries its "vassals", not allies.
Russia's warning on Friday indicated that it will seek to remove the reference to the transfer of power. But its insistence that details of a political settlement be worked out in talks seemed to leave little room for compromise.
Russia might be more pliable on other aspects of a resolution if it clearly rules out military intervention, said Fyodor Lukyanov, editor of the journal Russia in Global Affairs.
But he said Western and Arab states were unlikely to put recourse to the use of force entirely out of reach or bend far enough on the call for Assad to give up power to satisfy Moscow.
With Arab states such as Saudi Arabia and Qatar determined to get Assad out of power and Russia opposed, he said, "I cannot really see some resolution that could be agreed by all."
"This is not Libya, it's a completely different situation." (editing by David Stamp)