By Peter Apps, Political Risk Correspondent
LONDON (Reuters) - Western states trying to oust Syrian President Bashar al-Assad are increasingly struggling to deal with, or even understand, Russia's dogged support for him.
Arms deals, Russia's naval base in Tartus and fear of Islamist militancy in a post-Assad Syria are all held up as potential explanations. But Russian officials and some others say that misses the wider point.
They say Moscow's opposition to foreign-backed "regime change" reflects a fundamental disagreement with the West over sovereignty and the rights of states to deal with domestic instability by whatever means necessary.
"The Russian position can be explained by their hostility to any interference in the internal affairs of a country, especially in the current climate, because at home they have things to be worried about," says Denis Bauchard, a former diplomat and expert on the Middle East at the French Institute for International Relations (IFRI).
Time and time again, Western officials have confidently briefed that Russian President Vladimir Putin was on the brink of dumping his long-term ally, only to be disappointed.
On Saturday, Russian Foreign Minister Sergei Lavrov and counterparts from other major powers are due to meet in Geneva.
Once again, diplomats from several Western countries were predicting a shift. For the first time, they said, Russia had agreed with former U.N. Secretary-General Kofi Annan's plan and its requirement for a gradual transition of power.
But late on Thursday, it emerged that Russia had put forward amendments that the United States, Britain and France said were unacceptable.
At a Group of 20 summit in Mexico this month, British Prime Minister David Cameron was embarrassed after suggesting that Putin had agreed Assad should go, only to have Putin himself dismiss the idea.
French President Francois Hollande talked at length about the importance of winning Russia over, but had an awkward press conference with Putin in May having clearly failed to do so.
For every argument Hollande made before the assembled media, Putin had a counterargument. When Hollande asked if Russia would take Assad in exile, Putin replied that the Assad family had been invited to Paris much more often than to Moscow. While it is not clear that was true, Hollande still had to squirm.
Putin said the ousting of leaders did not necessarily lead to peace. He cited the case of Libya, where Moscow believes it was tricked by the West into supporting military intervention.
"Has it become safer there? Where are we moving? Is there an answer?" he asked.
Western states are still hoping that a series of military reverses for Assad will begin to tip the balance and force Putin to drop him. But it may not be that easy.
A death toll in Syria of well over 10,000 seems unlikely on its own to change Putin's mind. Estimates vary widely of the number of dead in Chechnya - a conflict in which he was involved as prime minister and president - but often exceed 100,000.
Rights activists and other witnesses say that conflict often involved artillery attacks on civilian areas, massacres and disappearances: potential war crimes now being reported in Syria.
Mindful of rising anti-Putin protests, not to mention separatist worries in the Caucasus, leaders in Moscow - and perhaps also Beijing, which has its own worries about unrest in Tibet, northwest China and many other areas - fear they might themselves have to adopt similar tactics again one day.
But it is the growing suggestion that Western democracies in particular might intervene militarily or otherwise to help such uprisings that really unnerves Russia's leaders, many believe. The 'Orange', 'Rose' and 'Tulip' revolutions in former Soviet Ukraine, Georgia and Kyrgyzstan have added to such concerns.
"Putin has spent the last decade obsessing about 'color revolutions'," says Stephen Sestanovich, principal State Department officer for the former Soviet Union between 1997 and 2001 and now senior fellow at the Council on Foreign Relations.
"He hates the idea that the international community has anything to say about who holds power in a country whose leaders have done something awful. He tends to sympathize with those leaders."
COST OF REVOLUTION
It can also be argued that the price of a revolution such as Syria's is simply too high.
"Russia probably knows the true cost of revolutions better than most other countries," Lavrov wrote in the Huffington Post on June 15.
"We are fully aware that revolutionary changes are always accompanied by social and economic setbacks as well as by loss of human life and suffering. This is exactly why we support an evolutionary and peaceful way of enacting long-awaited changes in the Middle East and North Africa."
Russian officials say they are not wedded to Assad but want stability to return, and have so far not seen a strategy that would achieve this.
There is little doubt that the situation in Syria also feeds into wider Russian concerns.
Many Western diplomats suspect Russia fears that Syria after Assad could become a haven for Islamists, not least those fighting Russia in Chechnya.
While Russia's naval base at Tartus is regarded as little more than a refueling stop, it does give Russia a Mediterranean harbor that could prove valuable if trouble with Ukraine or Turkey obstructed the operations of its Black Sea Fleet.
In Alawite-run Syria, and perhaps to a lesser extent in Shi'ite Iran, Russia also has a regional counterweight to an increasingly vocal bloc of Sunni Muslim-led countries allied with Washington, primarily Saudi Arabia and the Gulf states.
Some also suspect that Russia may see frustrating Western interests and embarrassing its leaders as an end in itself as it looks to reassert itself as a global power - or at least as a useful short-term tactic until a clearer picture emerges.
"In the West we often exaggerate Putin's dictatorial side," says former U.S. official Sestanovich.
"In Russia, many criticize him for indecisiveness. It may be that in Syria he's actually confused about what to do, and is slowly concluding that Assad has had it. That's the hopeful interpretation: Putin the conflicted ditherer."
(Additional reporting by Louis Charbonneau at the United Nations, Gleb Bryanski in Moscow, John Irish in Paris, Tom Miles in Geneva; Editing by Kevin Liffey)