Protests by hundreds of thousands of people in Ukraine against their leaders' like President Viktor Yanukovich' U-turn over Europe have sent a warning to Russian President Vladimir Putin that the battle over the former Soviet republic's future is far from over.
For once, matters may be largely out of the Russian leader's hands: he appears to have little left in his political armoury to woo Ukraine, especially if the protesters oust President Viktor Yanukovich or persuade him to change tack again.
There is no sign of Yanukovich quitting. But rallies by about 350,000 people this weekend, at times marred by clashes, have unleashed democratic forces which, for all his political calculations, Putin cannot control.
Public threats, such as cutting off gas supplies to Ukraine which could disrupt onward supplies to Europe, would risk stirring anti-Russian sentiment and do Yanukovich no favours.
"Yanukovich's big 'nyet' to EU followed by brutality against protesters could trigger Orange Revolution 2.0, wiping smirk off Putin's face," Strobe Talbott, a former U.S. deputy secretary of state, said in a tweeted message.
Talbott was referring to the "Orange Revolution" against sleaze and fraud which kept Yanukovich out of power in 2004.
Under pressure from Russia, Yanukovich dropped plans to sign a free trade pact with the European Union last Friday that would have steered his country of 46 million closer to Europe and further out of the orbit of its former Soviet masters in Moscow.
Instead he decided to rebuild economic ties with Russia. The sweeteners offered by Russia are thought to include cheap credits, cut-price Russian gas and trade incentives, and few doubt Putin also threatened Kiev with crippling trade sanctions.
It was a victory for Putin, but one which could yet prove pyrrhic - obliging Russia to support Ukraine financially when its own economy is stuttering - or be reversed.
Putin may be able to do little more now than offer even better terms to Yanukovich than those agreed in secret to try to prevent another policy zig-zag by Kiev.
DREAMS OF BIG UNION THREATENED
Putin is unlikely to stop pushing Ukraine to join a Moscow-led customs union with Kazakhstan and Belarus which he hopes to develop into a political and economic "Eurasian Union" to match the might of the United States and China.
Without Ukraine, its huge market, rich mineral resources and proximity to the EU's borders, building the Eurasian Union into a major alliance is probably mission impossible for Putin.
"Russia's policy is, in fact, an