BRUSSELS (Reuters) - Protests against Moldova's Communist rulers are the latest threat to stability on the European Union's eastern border but the bloc is wary of wading into a row that could stoke wider tensions with Russia.
Western diplomats say it is too early to judge whether street anger at alleged vote-rigging in a weekend election won by the incumbents will lead to a change of power, as seen in Georgia, Ukraine and other ex-Soviet states.
But Moscow's move on Wednesday to join President Vladimir Voronin in blaming neighbour and EU-member Romania for stoking the violence -- an accusation denied by Bucharest -- highlighted the risk of escalation.
"The EU should go and it should go now," said Andrew Wilson at London's European Council on Foreign Relations (ECFR), urging EU foreign policy chief Javier Solana to go to Moldova and act as a mediator between the government and opposition.
"But, yes, that would annoy the hell out of Russia," he said of the possibility for new Russia-West tensions just as U.S. President Barack Obama is offering Moscow a fresh start.
Europe and Russia have been jostling for years over the group of ex-Soviet states Moscow calls its "near abroad" and which Brussels refers to as its eastern neighbours.
Moscow sees NATO's enlargement eastwards as an aggression, while Europe and the United States accuse Russia of using its dominance to bully neighbours.
Ukraine, the main transit route for Russian gas exports to Europe, clashed with Russia in January in a dispute that cut supplies to many European countries in the middle of winter.
A fresh dispute over supplies is now brewing between the two neighbours, and oil and gas export routes to Western markets are a constant source of tension between Russia, its former Soviet satellite states and the West.
Russia has flexed its military muscle too. Georgia lost a five-day war with Russia in August when Moscow sent in troops and tanks to repel Tbilisi's bid to seize back a pro-Moscow breakaway region.
European reaction to events in Moldova has been cautious.
So far, the EU has agreed to send a special envoy to the capital Chisinau to monitor events but there has been no talk of any direct role, a diplomat close to talks said.
In a statement, the bloc urged all parties to refrain from violence but stressed the right of protesters -- many of them pro-EU -- to demonstrate in peace, noting election observers were not fully happy with how the vote took place.
With Voronin's allies having regained control of parliament and presidential offices occupied by protesters on Tuesday, EU diplomats pointed to a relative calm on Wednesday and said the bloc planned no further steps at this point.
Fitch Ratings agency said Moldova's credit rating could be threatened if the political unrest persisted but said the fallout to the rest of the region appeared to be contained.
"People are trying to say this is some kind of Ukrainian 'Orange Revolution', which for us makes no kind of sense," said Commerzbank strategist Luis Costa of the 2004 protests in Kiev.
But any impression of a lull could be misleading.
Joanna Gorska of consultant Exclusive Analysis said anger in Moldova had been exacerbated by an economic crisis that has hit foreign investment and led to a fall in remittances, a main source of income in Europe's poorest country.
"The closest comparison would be Ukraine, where again the economic crisis has come on top of existing political instability," she said of a collapse in Ukraine's economy which has triggered protests at job cuts and falling living standards.
The unrest broke out at a delicate time in efforts to solve the "frozen conflict" in Moldova's Russian-speaking breakaway Transdniestria region, a source of instability in Europe's backyard since the end of the Cold War.
Moldova, Transdniestria and Russia agreed last month that a European mission could replace Russian peacekeepers there after any peace deal is concluded.
"In terms of the Transdniestria dispute, there may not be any direct impact but obviously to resolve that you need stability in Moldova," Gorska said.
In the short-term, the troubles in Chisinau could add to the uncertainties hovering over the May 7 launch in Prague of an "Eastern Partnership" scheme for enhanced economic and political ties between the EU and six ex-Soviet states, Moldova included.
Already there were doubts over whether Belarussian President Alexander Lukashenko can attend the summit given concerns over human rights in his country.
On Wednesday the EU would not comment on whether Voronin's accusations of meddling directed at Romania would be a factor in whether he was invited to attend.
"No invitations have gone out yet," an EU Commission spokeswoman told a regular briefing.
Additional reporting by Sebastian Tong, Carolyn Cohn and Peter Apps in London; Editing by Angus MacSwan