Three years ago, a Russian gas dispute held consumers hostage and the European Union swore "never again."

It launched plans to diversify energy sources and transport routes and called on member nations to stockpile more natural gas. But again it has been caught in the cold this winter as Moscow turns off the taps amid a wrangle with Ukraine.

The crisis raises the question of what exactly the bloc has achieved in the years since it vowed to change course on energy policy. The stark answer, in practice at least, appears to be: very little.

Europe's growing dependence on Russian gas has been no secret: Russia's share of EU gas imports is projected to rise from 40 percent now to 60 percent by 2030. A quarter of the EU's gas comes from Russia and 80 percent of it flows through Ukrainian pipelines.

Cutting supplies has left thousands of homes and businesses without heating for a sixth day Monday amid freezing weather.

"We didn't need this crisis to kickstart our own reflections on the matter," said EU spokesman Johannes Laitenberger.

But the EU faces formidable obstacles in weaning itself away from Russian energy.

Any united answer has always met with objections from some of the 27 member states. And grand plans to find new energy suppliers and boost alternative sources such as wind power have run into cold truths: there aren't many options and change is expensive.

One alternative is importing more gas from Iran, which holds one of the worlds largest natural gas reserves. But few believe Tehran — which is engaged in a tense standoff with the West over its nuclear program — would be any more reliable an energy partner than Moscow.

EU governments have squabbled over how to deal with Russia and dragged their feet over spending the billions of euros needed to upgrade energy infrastructure and switch fuels.

In particular, member nations have been reluctant to give the EU's executive Commission the power to deal with energy suppliers on their behalf and decide which is most trustworthy — a key step in crafting a unified EU gas market.

For Germany — Europe's largest economy — Russia is a partner: Surging imports of Russian gas are key to its plans to turn away from coal and nuclear toward cleaner low-emission energy.

But Russia is hardly a trusted friend to the many eastern European nations that joined the EU in 2004 and once formed part of the Soviet bloc. Thorny disputes over Polish meat and an Estonian Soviet war memorial have held up an EU push to sign a major economic pact with Russia.

The EU's reluctance to get drawn into old arguments — and its insistence on separating politics from business — left it without a ready response when the row between Russia and Ukraine exploded last week.

EU officials claimed at first that it was a purely commercial dispute and the countries' gas companies — both state-owned — should live up to their promises and restart gas supplies to Europe even if they weren't supplying each other.

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